Good advice above, I am not new to parties but if going to one I haven't been to before I will tell the organiser, as well as showing you around experienced organisers will keep an eye out for you or ask the girls to.
Most parties have a lull after a few guys have come, usually quite quickly, so you can get the measure of the party and join in when it is a bit quieter.
Don't worry about being a voyeur, you are paying the same money. Same goes if you just want oral, doing RO, so long as the girl offers it do what you want.
Don't overdo drink or take drugs, it will be obvious and get you thrown out. Change condoms and don't throw used condoms on the floor for some other person to tread in.
Don't take expensive stuff if you can at all avoid it, parties will have a secure system for phone and wallet but often harder to stash laptops and easy to worry about it, ruining the experience.
Don't worry if it isn't for you, I went through a phase of loving parties but haven't been to one for ages, partly due to Covid and partly not as interested as before.