This might help: https://youtu.be/yIiyWbQZBuE

It is a video on church etiquette for beginners.

Sober, alien, and contemplative

The Mass is supposed to feel otherworldly (because what’s happening is actually supernatural), it’s supposed to be a place of communal prayer, but also be a place where you as an individual can come closer to God. (So not a lot of stress is on forcing external social interactions: although we’re all praying in a “mass” growing in your relationship with God is just as if not more important here.) It’s also an opportunity to contemplate the Word, and to become more informed on what the church teaches about Him, in the form of the readings and homily.

Just remember that what’s happening is a sacrifice, a group prayer (in fact there’s no better prayer than the Mass), and an opportunity to obtain Graces, and you won’t need to understand anything else that’s going on. (And also please refrain from receiving the Eucharist, although it’s the Flesh and Blood of Our Lord and the price paid for our sins, eating It is reserved for Catholics.)

Hope you can attend, and I will be sure to pray for you today!

To answer the question, its a congregational of worship with a purpose, outside of something metaphorical. The Mass, if it wasn't beautiful, if it wasn't engaging, if we reduce it down to its core parts, it is an direct experience with Christ in the Eucharist. And this doesn't mean you need to partake in it; watching it being consecrated and the reverence around this process within the parishioners lets you in enough about what's going on and how its important.

Sit in the back so that you can watch others with little worry about others watching you. As other posters indicated, you'll be able to follow the pattern of the congregation in terms of standing and kneeling. Don't go up for communion, but watch others go, so you get an idea for how it's done and you'll be more comfortable when it's your turn after confirmation. Most churches have a printed order of service that you can follow along with, as well. They often say the pages in the Missal that certain prayers will be on . The Missal is in the seatback in front of your pew.

Stand when everyone else stands, sit when they sit, and kneel when they kneel. If you don't know the responses which people say during mass then just don't say anything, you'll pick them up eventually. Just don't receive Communion.

I doubt anyone will judge you if you mess up, I think most of us have done a mistake sometime.

Nobody will care if you don't do everything correctly (just don't receive Communion*).

Having someone walks you through the different parts of the mass can highly improve the experience though, so if it's possible I'd advise going there with some Catholic you know and trust.

A missal or at least a cheat-sheet of the order of the mass might help if you want to know what people are saying

As a visitor, you may participate as much as you wish, with the exception of receiving communion. For your first time, you might feel most comfortable sitting quietly and observantly throughout.

Mass comes in two parts: the liturgy of the word and the liturgy of the Eucharist.

The priest will greet everyone and offer some short prayers. The liturgy of the word typically consists of three readings from the Bible with short responsal psalms in between. After the third reading, which is typically from the gospels, the priest or a deacon delivers a homily. After that is the creed. Then is the presentation of gifts. People spend a lot of time kneeling during the liturgy of the Eucharist as we are humbling ourselves before the presence of God. After communion, the priest will make some announcements and offer a closing prayer. During the closing hymn it is considered rude to leave before the priests procession exits. That usually takes a full verse and chorus of the hymn.

Our church has mass guides in the pews in a small binders. Others may do the same. Just follow what others are doing but don’t join in communion. Your church of choice may have greeters and tell them it’s your first time attending mass. They are very helpful.

I can’t really compare to any other church service since last time I went to a Baptist church I fell asleep(I was like 12 btw) which was unusual for me even then. But just know that it’s glorious

I think it’s important to clarify what to do when people say not to receive communion. When everyone else gets on line to receive, you can stay in your seat. You won’t be the only one, just let other people get by. The other option is to get on the line where the priest is distributing (not one of the non-priest Eucharist ministers) and leave your arms crossed in front of your chest. This will show the priest that you don’t want to receive but instead just want a blessing - he will just say a few quick words, like 2 seconds, while maybe putting his hand on your head. You can return to your seat afterwards.

They took the kneeling pads out at my parish : (

Just go... everyone is welcome.

As others have mentioned, just sit in the back half, and do what others do in regards standing, sitting, kneeling, etc. Just don't get up for communion (others wont either).

And....let us know how you felt about it when you go.

Here's what really happens at Mass: https://youtu.be/OOLZDaTgIaM

Of course experiences vary, but this video depicts what actually happens supernaturally.

Liturgy

The Veil Removed https://youtu.be/OOLZDaTgIaM

Elements of the Catholic Mass https://watch.heroicmen.com/the-elements-of-the-catholic-mass-1

Understanding the Mass https://youtube.com/playlist?list=PLIEHvf1_M4UvQIeqw0LI6m-ahSS5jqjDZ

Real Presence Series - Augustine Institute https://watch.heroicmen.com/presence

General Instruction of the Roman Missal https://www.vatican.va/roman_curia/congregations/ccdds/documents/rc_con_ccdds_doc_20030317_ordinamento-messale_en.html

Nothing to be scared or nervous about. We’ve all been there..Just go. No one will judge you. Maybe watch some online beforehand to get the feel of how it goes. You don’t have to do anything really. Just sit and watch (or follow what others do). After a few times you will get the hang of it and be a pro.

Print this off and you'll be able to follow along. It's a one page guide. Just don't receive Communion (but you can get in line for a blessing!).

https://catholic-resources.org/ChurchDocs/Mass-BasicTexts-Rev3.pdf

I usually go and sit at the rear seats, and copy what other people do, and enjoy the atmosphere of the mass. if you are not a catholic, when you go for the bread, you just cross your arms and get a bless.

Learn by observing.

Watch carefully and mimic them.

Basically just sit, stand and kneel during most of the Mass, and during the sign of Peace, just look at people around you, and say "Peace be with you" or what I say "Peace of Christ" while nodding or bowing your head a little bit.

Be quiet, dignified, and respectful, and you will be welcomed.

You can go up to Communion, and cross you arms for a blessing with your head bowed down, or just stay seated. Some people don't go up, so don't worry about it. If the Priest offers you Communion, just whisper, that you want a blessing, by saying "Bless me Father" and bow your head. He will understand, and give you a blessing.