if your just starting out, getting air off ramps should be first, then when your more confident, you could do x-ups (turning you hadlebars, but keeping your hands on) one foots (try and start doing these by putting the foot you will be keeping on the bike, say you were kicking the right one out, and the left was staying on the pedal, make this foot be at the bottom of the crank, instead of being balanced with the right one. This will make it easier to get the foot back on) then from there you could do can-cans, nofooters, supermans, indians and eventually tailwhips. all of these tricks originate from doing no-footers.
Taking your hand(s) off is a bit more complicated, as you have to pull up a bit harder on the opposite hand to the one you take off, to balance the bike out. Try just taking your hand off a fraction, then a bit more, and more as you get better at it. no-handers require you to grip the part where your bottom and top tube on your frame with your knees. this keeps the bike near enough to get the hands back on. From no handers you can do barspins, peg grabs, toboggans, suicides and seat grabs.
If all of that fails you can try spins. first try 180 degree bunny hopping on flatland, as this is essential. Lift your front wheel round the first 90 degrees, then pop the back end round the rest. From here, you can do this on ramps, but instead of riding fakie, slam the back wheel hard onto the top of the ramp after the 180, pull the back brake, and spin the final 180 degrees or whatever on the back wheel. I tried to do this for two months, but once you do it once, you can do it anytime, and it looks great.
Finally, just remember to have fun. TJ Lavin and Dave Mirra etc, are about 25-30, and you are probabaly nowhere near that age. Grind ledges, bunnyhop kebs, do manuals, wheelies etc, then when you are happy with then go out and ride. And the most important rule in this is PRACTICE DOESNT MAKE PERFECT BUT IT MAKES YOU BETTER EVERY TIME.