Most new guitars come strung with light-gauge strings. For beginning players, that’s probably a good place to start. As you develop and your fingers gain calluses and strength, you may want to gradually move up to heavier strings, depending on the music you play.
Heavier gauge strings:
are generally harder to play
require more finger pressure to fret and bend notes
produce more volume and sustain
are preferred for low tunings such as drop D
exert more tension on the guitar neck