Welcome to the Forum! the first thing you should do is spend as much time playing with your phone, and figuring out what it can do. it's an excellent OS, and has a pretty steep learning curve. but, you do have to spend time with it. after that, you'll have an idea as to what you may not understand, and what may require further investigation. then you can browse and search around in here - tons of info, and even more friendly people!
as to what you shouldn't do... DON'T install any kind of task killer or anti-virus app (if any are on there, uninstall them. these just work against the Andy OS, and end up causing more problems than they solve. also, DON'T hesitate to ask questions - we're here to help and share info/ideas.
jump in, get involved, stick around, and join in the fun!