I wanna go to a party, but want to make sure I won't be in trouble for the alcohol! ?

There is the party that I got invited to that has alcohol and stuff! The host is my good friend and I would like to go and see my friends and have fun! It's a huge party with like 200 people going and it going to be gigantic! However, I am only 19 years old and I cannot even drink alcohol because I'm on medication that prevents me from drinking so I've never consumed beer, margaritas, etc. And I never plan to! I was Told it was a private party and it cannot be busted. Is that true? And would I get arrested if I tried to get into it and they ask for ID and find out I'm not 21 at the entrance to the party? Also, if cops bust it somehow, do I get arrested even if I didn't drink? I don't plan on going if there is any chance to get into trouble. And this is in texas btw! Thanks