For jumps and rails, you don't really want a super soft board because they wash out in bigger jump landings. Medim-soft boards are what i like here
I ride a salomon villain in the park, a 147 would probably fit you well, seems short but it has blunted tips which makes it ride longer.
Other good ones would be Capita Ultrafear, Flow Verve, Signal Park(any camber shape you like they are all good). Any of those in a 150ish size. There are lots of others that would work but these are ones i like.
Dude, suckin at somethin' is just the first step to bein' sorta good at somethin'