It will! Actually I found, having read stuff about using gears, that I'd been doing the right thing all along by instinct, ie using the big ones on the left as the main changes and then tweak about with the right hand ones. You'll do most of your cycling with the number "2" appearing by your left hand - certainly to begin with!
"Cadence" is a training buzzword which basically means how fast your pedals are going round. If you're pedalling really fast you could probably go up a few notches on the righthand gear. If you're puffing away with the pedals going round slowly, change down! - soon you will be doing it exactly as it suits you.
When you change gear, keep turning the pedals but don't grind them - slightly "soft pedal" for a moment as you pull/push the lever or twist the gear change. If you're grinding up a hill and change without soft-pedalling, your chain can come off (easily put back, but oil all over your hands!).
Your bike shop people will show you!