I think I have used nearly every kind of strings made on at least one of my three Fender Strats. It honestly doesnt matter all that much. Not nearly as much as your pickup choice. I like Elixers, I like plain old D'Addario's, and I like the Fender Bullets. The cool thing about bullets is that they're made to fit your Strat's tremelo and fit perfectly snugly in there. I do think it may help a *bit with sustain. Being a new player, you have years and years to try out different strings for yourself and find out what you like. I've also used DeanMarkleys, the DR strings, Super Slinkys, the Blue Steel Cryogenic Strings, various GHS, and 2.99 Guitar Center specials. They all work, you'll get the feel for what you like over a long period of trying stuff out.
H2H