The downside of wearing a belt is that it takes the core muscles out of your lifts. This actually worsens than problems rather than improve it. Why not strengthen your core and lower back muscles so they can do their job properly: stabilize your body during every single lift. As a beginner, you shouldn't be going so having that a belt is necessary.
Generally speaking belts should be left to powerlifters (because they move serious tonnage) and bodybuilders (I've read they use belts to "shrink" the waistline or something along those lines).