Some bigger skaters get wider, or larger boards to compensate. That does work, but mostly only if you want to stick to ramp riding. If you want to do tricks, you’ll still want a smaller board. Having a smaller skateboard just makes doing technical tricks so much easier. Yeah, your bigger feet will get in the way, but with practice you’ll do just fine.
So, my suggestion to most larger guys is to just skate like anyone else. And, just like any other skater, if you find yourself wanting a larger board, then go get one. But I wouldn’t say that getting a huge board is the key, or anything like that. Really, the key is just more work! It’s not the answer most guys hope for, but it DOES work out!
One thing you can do though, is wear more padding. When you are bigger, you get hurt more when you fall. And when you’re taller, you just fall more. So the combo can be pretty vicious. If you can stand looking lame, wear some pads. Always wear a helmet, plus maybe some elbow pads, wrist guards, knee pads if you are on ramps, or even padded shorts. By no means do you NEED to do this, but you CAN! And if you are nervous about looking lame, well, aren't you bigger than everyone else!?
So, the bottom line is, if you are a larger skater, unfortunately there isn't any quick fix to get good at skateboarding. It's going to take work, but not an unreasonable amount. On the plus side of being a large skater, if you collide with anyone at the skatepark, they will likely lose in the exchange. People won't mess with you as much. If you take to bombing down hills, you should be able to get up to wonderfully dangerous speeds. Plus, if you get at all good, you'll attract more ladies than puny skaters.
See, it all works out! Relax, have fun, and take learning to skate at your own speed. Don't compare yourself to other skaters - enjoy yourself, keep practicing, and you'll learn to skate just fine!