This is the problem with some people. They are so competetive that they end up making a fool of themselves. There is nothing wrong with being competitive but you need to direct at the appropriate time. Go in there with a humble attitude. Just say to yourself "I'm here to learn, not to be the best". There are people who are better than you. Accept that and learn from them.

This may seem like strange advice at first but, don't worry about screwing up. Screwing up is part of the process. It's up to the instructor(who is hopefully of good quality) to guide you.

You're new so they can't enforce the whole curriculum on you the first day. To do so would be unreasonable. Instead they would teach you the curriculum one step at a time.

If you're too worried about doing everything right the first time it will actually get in the way of your progression as it breeds hesitation. It's not some mystical mumbo jumbo, this is legit advice.

If you were able to do everything perfectly the first time then what would you need an instructor for?

just observe carefully and pay attention all the time. the most you can do is stretch out often before and after these sessions because you can expect alot of muscle activity. if you learn karate little by little, you can practice by yourself or use a punching bag if you want to. do not practice on other people except the ones in your class, when given permission to do so.

Lie low and be respectful to everyone, this is what majority of instructors want.. "discipline" when you have it, it will surely make you up in the class..

Don't talk crap and act normal...? Anyone should know this.

How do I not make a fool of myself in the first class? I believe I will take on Karate. What should I do in preparation for the beginning? I would LOVE to be ahead of training whenever I join so that I can easily be on top of each lesson and practice tons at home.