My advice is don't be discouraged by asshole comments on the internet. Contrary to the impression you might have got from some of the asshole comments on this thread, I think you will find that everyone is supportive at meets in real life and you will have a great time and learn alot. And meets have weight classes for a reason.
I have been PLing for 18 or so months and have been to two meets and I had a great time at both of them. I am not going to be a pro powerlifter either, and I'm over 40 and carry extra fat. I didn't let that stop me or feel the need to wait until my body composition met someone else's idea of where it should be. Again, everyone at both meets I went to was very supportive and did not look down on new lifters, regardless of their weight class, age, or experience. The most important thing is to work hard and keep improving.
What fed are you lifting in? Do you have any specific questions? I'll do my best to answer them from the perspective of a guy who is also relatively new to the sport but who has two meets under his belt.
Good luck at your meet,