I wouldn't do the trigger yourself. 40 bucks-ish with a gunsmith. Same with bedding. If you're looking to make your rifle more accurate, those are the two big ones right off the bat (in that order, in my opinion), along with getting a decent scope, as mentioned.
The thing with doing it yourself is those two things are fairly easy to screw up if you don't really know what you're doing, and screw up your gun along with it. Both are cheap mods, so I'd just spend the money. Also, both those things have a little bit of an art to them, best left to someone who's done a truckload of them.
Something you could do yourself that will really help your accuracy (and your wallet) is to learn how to reload. If you're not ready to do that then -for now, just shoot lots (at little targets), save all your brass.