Even though I'm from Chicago (and love Lou Malnati's deep dish), I prefer a good thin crust pizza. There's a place near my hometown that had the best version. I grew having it every Friday night. I spent years trying to perfect it, realizing that if you change one ingredient... it changes the entire pizza. The sausage needs to be mild and not that Johnsonville crap. I tried every imaginable mozzarella (from Trader Joe's to Kraft to gourmet stuff) until I found that Sargento's worked best. The sauce needs to be the same, too. Nothing fancy. Classico's Traditional sauce does the job.
What you need...
Start by partially cooking the Italian sausage (not too much; just enough). Set aside on a paper plate. Melt some butter in the microwave (about 30 seconds; cover it; I use a tiny glass bowl). Put the pizza crust on some parchment paper. Brush the melted butter over every nook and cranny. Spoon the pizza sauce on (I like a lot of sauce; same thing... cover every inch, ideally by hand; I use disposable gloves). Take a few handfuls of the mozzarella and spread evenly. Crumble the sausage and spread it out (not too much, but ideally every bite should have a piece). Put the veggies on (same; spread them out; every bite should have some). Put down another few handfuls of cheese (just covering everything; don't use too much). Sprinkle a little Italian seasoning over the pizza and do the same with the cracked pepper.
As for your oven... if it's lavash bread (thin, cracker-like crust), go with 400 for about 17 minutes. Put it on the middle rack. Turn the light on about 10 minutes in. Once it's starting to brown (i.e. looks like the pic), take it out. If it has its own directions (I think Boboli is about 425), that's fine. Just keep checking (without opening the oven door). You want to make sure it's brown (like my pic), but not TOO brown.
Take it out. Cut into squares. Enjoy.
I typically make about 5-6 on a weekend. I eat one of them and vacuum seal & freeze the others. Why? I now have homemade frozen pizza ready within minutes.
Just some musings from an old guy...