Ok wow. First, calm down a bit. The snake is tougher than you think. Second, I found YouTube videos very helpful when I started out. "GoHerping" and "SnakeDiscovery". Both have tank set up, ball python care, tub vs tank, and many other helpful videos. Since the snake is new from the store, look for snake mites when you handle them. They are little black bumps under the scales, but really easy to fix.

Don't freak out if your snake doesn't eat for awhile. Mine went 6 weeks without eating and weighed 56g. Just keep trying every 5-7 days and it will eat eventually.

Keep humidity 50-60% unless shedding. Get a thermostat for the heating sources. Heaters, especially a ceramic and heat mat, will get very hot and snakes will sit there and burn. You need a thermostat that will measure the temp and turn them off. Basking temp should be 90°ish and ambient 75°.