Mountain biking in winter park or breck

I've done it at Winter Park. I just wore my normal workout clothes. I didn't take a lesson just took it easy the first time down then progressively went faster as I got more confident in my riding. Be sure to get the insurance on the bike if you rent one b/c they cost a lot to fix. I would also recommend getting a chest protector if you get confident enough to take on some of the jumps. Use the back break more than the front so you don't flip over the bars

Both have good areas and trails. Depends on what you want to do. Lift to the top and bomb to the bottom, or, nice single-track with priceless views?

Not sure what kind of "lesson" you want, but, you can pretty much rent all of your gear at any of the areas.