Here are a few tips on classroom etiquette, which will help both you and your fellow students (not to mention the teacher) get the most out of your convention experience!
Choose classes at a level that you know you can fold. Although it is often tempting to "stretch" your folding ability, the best place to do this is in a very small class, in a one-on-one session or in a class specifically designed to teach new techniques. In a large class, when the teacher has to wait on one student, then that holds up the whole class. (In theory, if someone is clearly below the class level, the instructor would proceed without them. In practice, it is hard for an instructor to bring him/herself to abandon someone, so what generally happens is, everyone waits).
Please show up on time. If someone is late, either the instructor leaves them behind (which is no fun for them), or the rest of the class waits for the person to catch up, which is no fun for the rest of the class.
If you want to record what you're learning, the best way to do this is to take pictures as you go, rather than folding multiples or sketching diagrams. You should ask at the beginning of the class if the teacher minds if you do this; it's almost always OK with the teacher, but it's good to check first.
Watch what your neighbors are doing. If your model differs from theirs, actively compare what you're doing; one of you is probably wrong, and the one who's right should be helping the other. If you can't figure out who's right, ask the instructor.
If the instructor is helping one individual, wait till he/she is done with that person before you request attention. Conversely, if you are done and others are still struggling, please be patient; we want everyone to finish successfully!
If you're a quick folder, it may be tempting to try to do or anticipate the next step. Be wary, though: some artists like to do surprising moves in their instructions. Please resist the temptation to ask, "is the next step X?" If the next step is X, the instructor will almost certainly tell people when it's time.
Ask permission before handling another person's paper, even if it looks like they need help. (This goes for instructors, too.) If many people are having trouble and you're not, you can help by offering aid to those around you who are struggling; but per previous advice, offer first, and wait for acceptance of your offer before you dive in.
If you are falling behind, you are welcome to ask the instructor to wait. The farther you fall behind, the harder it will be to catch up (and the more likely it will be that something important gets left out as you're trying to catch up). There's no shame in asking the instructor to wait; they want you to succeed, too!
If you realize you've taken on something beyond your abilities, you may leave or just stop folding. Don't feel bad--everyone has experienced that at some point in their origami life--and the instructor might be available to give you some one-on-one help outside of class.
If you suspect that your skill level is borderline for the class, you may make arrangements with a friend, colleague, or the person next to you to ask for help.
While there are relatively few folders with physical disabilities or hearing impairments, there are some; please be sensitive to their need to pay more attention to the instructors and to their own folding.