First of all, you need a helmet to protect your head. You can still get concussions and all that but it lessons the chance of that happening.
You need this to protect your shoulder, collar bone, and chest. You can still break/fracture them but lessons the chances
You need a mouthguard to protect your teeth from falling out because the impact of a hit is strong enough to do that.
You need these gloves cause they have a stickiness to them that will help you catch the ball. Cleats will help you have a firm grip in the ground when you take off and will help you not to slide on the grass.