Huh. Never had that issue myself, with the crust burning and the middle uncooked.
First, if using a pizza stone, you have to preheat it for at least 30 minutes, preferably 45 or more. I put the cold stone in the cold oven while its preheating (although I don’t bother with pizza stones anymore.) I do my pizza hot, at 500F. 450F is the usual recommended temp, so start there.
I assemble the pizza on a lightly floured or cornmealed pizza peel. If you don’t have one of those, you just need something that you can slide pizza easily off onto the stone. When everything is preheated, I take the dough, form it into a pizza disk (I use my hands, you can roll it), top it, and throw it in the oven immediately to cook until the cheese just starts to brown.
Now, a little more detail. I add a fairly thin layer of sauce. I spoon or ladle a bit of sauce in the middle, then make an ever larger circular pattern with the spoon/ladle to spread the sauce outward towards the crust. I then add my sausage or pepperoni, mushrooms, cold cuts, etc., and then top with a sensible amount of shredded cheese.
If you’re using fresh mushrooms or very watery vegetables like bell peppers or zucchini, it often helps to precook them slightly to drive off some of that moisture. With mushrooms, I generally use them raw, but slice them thinly and don’t overload the pizza with them, as they will make the pizza soggy. If I want to make a full-on mushroom pizza, I will precook the mushrooms a bit, otherwise, you’ll get a soupy mess. Likewise, you can get away with a couple raw onions and raw peppers, but crowd them too much, and it will get soupy. I find that high heat helps with this, too. Cooking my pizza at 500F, it seems the pizza cooks before the vegetables let go of too much of their moisture. At 400-450, it’s a bit dicey, depending on how loaded with veggies the pizza is. If it’s a veggie only pizza, I will precook all the vegetables slightly. Even better is roasting them, so you get the additional roasted flavor as well as solving the too-much-moisture problem.