**Hi gin gin,
You will do fine. I would suggest going maybe half an hour early the first time, just to check things out.
You will walk in, and you will find a little font with Holy Water some place near where you entered. You dip a finger into the Holy Water, and make the Sign of the Cross. You would then proceed to a pew. Before you get into your pew, you kneel on your right knee and make the Sign of the Cross, then move into the pew where you want to sit. If you do go a little early the first time, before you get into your pew, you may want to walk around the church before Mass, to just look at things.
Just remember that anytime you cross the giant crucifix up at the altar, you face the cross, and kneel or bow and make the Sign of the Cross, then proceed to the other side.
Just follow along and do what the others are doing if you are comfortable, or you can just sit and take it all in. If you are sitting when others are kneeling though, it would be polite to just inch up a tad so the person behind you isn’t breathing down your neck.
There will be a part of the Mass where we offer those around us the "sign of peace’. You would then shake hands and smile to those around you to show them you mean them peace, not ill will. As you shake their hand, you can just smile, or say, " The Peace of God Be with You ".
When it’s time for Communion, each church kind of does what works best for them. You may have the people go up row by row, or they may all go up haphazardly at once, and wait for an open spot to receive Communion. Until you have officially become a Catholic, as others have said, you would remain in your pew for Communion. All you would do is to push the kneeler up when others are getting out, then bring the kneeler back down again. If people are trying to get back into the pew, you would then be polite and raise it back up for them so they aren’t trying to walk into the pew with the kneeler in the way.
You may see people after they come back from Communion cover their faces, or put their hands across their eyes. They aren’t about to pass out or anything,

, they are just spending a little private time with Jesus before they swallow Him and they become a part of each other.
When the Mass is over, you would then do again what you did as you entered.
Another option is to call the church and just ask what hours the church is open, and to check everything out when no one else is there. I think if you get a
" feel" for the church before your first Mass, things won’t be so scary.
Relax, you will do fine !

**