As you move up certain things are easier and the catchers usually much better, but more is expected too and until the game slows down in your head, then it doesn't really get any "easier".
The best $10 you ever spent on equipment is the most important at U12... Or you could spend $40 on the nutty buddy (look it up). Beyond that one piece - get a good chest protector - you'll need it later anyway.
As always the number of times you get hit depends on your catcher's ability to block the ball. Depending on the rules, some U12's don't always put their best player back there. For instance some local rules don't allow "stealing" on a wild pitch or passed ball - so if you're a coach that "knows" how to use the rules - you put your worst fielder back there. Of course the coach eventually wonders why his pitcher isn't getting any calls ;-)
As you move up - the next invention that will get you is the hard curveball off the edge of the plate that has been known to sneak up under the cup. As always there's the pitch above the hands that the batter invariably nicks off his bat and into your body somewhere. Remember that's a pitch you don't call a strike, but the batter swings anyway... then the same batter looks at strike 3 on the outer edge of the plate and complains. Uhm - who swung at ball 4 two pitches ago? ;-)