Here are a few tips that I have for you.
First: Keep your mouth shut and your ears open. Everyone there (including the techs) know more than you do.
Second: Know what you're allowed to do, what you can do with supervision, and what you may never do under any circumstances. I used to call that last one my "never list."
Third: Be an active learner. Seek out opportunities. If there's a code, ask if you can help. They'll probably put you in the queue for doing compressions. Like most of us here, we've worked codes enough that it's fairly routine for us to do compressions or any other intervention.
Fourth: Ask your preceptor (usually a nurse) if you can practice doing vitals and doing basic patient assessments. Then with each patient, ask the preceptor first and then the patient for permission to do it because you're a student. Don't just mimic what you see your preceptor doing or other staff... we've been around a while and we do very focused assessments so we might not actually do a full-up patient assessment, though if I were to do one and not narrate while I'm doing it, I could get a reasonably well-done assessment done in less than 5 minutes, and at the EMT level, less than one, minus actual vitals (I off-load that task to a machine because I can).
Fifth: have your paperwork with you so we can sign off completion of skills OR so we can reference what you can and can't do. Also if you have to do some documentation, get it done when you can (like when your preceptor is documenting too).
Sixth: have fun!