Be painfully honest about whatever you don't know or are unsure of, and ask someone who does. Learning as a new diver is not the time to try to save face.
Become friendly with your rear dump valve, it will help you get "negative" so you can descend from the surface, starting when you're horizontal and more so when you're angled head-down (e.g. on a boat's anchor line that's tied into that wreck).
Make those first few dives as "un-challenging" a venue as you can--not too deep, not much current, decent visibility, not too cold. These "boring" dives (actually no dive is boring, but anyway), it will be easier for you to snag a buddy who is better than you (which at the beginning, means all of them). That better diver will be more willing to buddy with you if the dive isn't that "special" or challenging, because he/she isn't "giving up" that much if they have concentrate more on you more than on their own wishes or ambitions.
Believe your gauges. They are right. Especially your compass if you're in poor visibility. Practice with your compass on shore. If you're doing an "out and back" dive pattern, look back occasionally on the way "out", so you'll know better what it's going to look like on the way back "home" to the up-line.
Remember the wisdom phrases from class: "If you can breathe, you can solve all your other problems", and when you want to panic over something, "Stop. Breathe. Think. Act". That way, if you get into a bad fix (reg and mask knocked askew, negative buoyancy, disorientation, darkness), your first voice won't be "oh no I'm done for", but rather, "wait---we covered this in class". (i shall not go into detail as to how I know this ;-)
Farther down the road.. once you've gotten some experience from those unselfish more-experienced buddies who were willing to bring you along, remember to be like them when it's your turn with a newbie. Pay it forward when you can.
Best wishes.