Our son was around the same age when we first took him to a water park - he too wasn't a "big" water kid. We took him to TL and it was fine - -there were areas for him to have fun and such, but to tell you the truth, it wasn't worth the extra money or time (in our opinion). DS had and has more fun in the resort pool. With the water park you had to find an area to put your stuff, but still needed to move around to other areas not so near by if you wanted to try other things. I personally think the water parks are best for families who truly enjoy going down water slides and such..for us it was nice to say we tried it, but we haven't done it again since and unless our son all of a sudden REALLY wants to go again we probably won't in the future.
Both water parks have areas for little kids - so either should be fine. There are mini golf courses near BB so that might be something fun to try if you're in the area. Even though we're not big fans of water parks (that's just us) I think you should try it at least once if you're curious. For some reason we went with TL because it seemed like the least "adventuresome" of the 2 water parks and there might be a little more for DS..also I thought BB might be a bit more crowded because it does seem to be the more popular of the 2.