Hi!
Welcome!
At 9 months he probably still has his puppy coat and they can mat easily. You'll need a fine tooth metal comb to gently comb thru the hair all the way to the skin to work out the mats. A detangler will more then pay for itself in helping with the real problem ones. Brushing alone simply won't reach the mats that develop close to the skin. Search in the Grooming section here and also the Product sections, you should find several threads discussing the different combs available. But to start with you should be able to find a fine tooth flea comb at any pet supply store.
Trimming the hair on his belly and along the inside top of his hind legs will help with the pee problem. I also have baby wipes that I leave by the back door and wipe Yogi when he comes in. He is 3 months old and squats to pee so often has some...errr...overspray issues.
And of course, please post some pictures of your little man when you can!!