You need to read the stickies in the husbandry forum and main page, as they will help you tremendously with your questions.

As far as the UTH, are you regulating it with a thermometer? If not, you must remove it IMMEDIATELY. UTHs that are not regulated can (and often do) easily overheat causing burns to your snake. The UTH is not going to raise the temp in the tank, they are only designed to heat the underside of the tank so your snake can warm its belly. Again, if it's not being regulated, remove it until you get a thermometer.

As far as cleaning the tank, use what you prefer. There are many options. My personal favorite and most recommended is Pro Products' "BioShield." It's non-toxic to any animal but kills bacteria and fungus and even works underwater.

I would advise getting either heat lamps or Ceramic Heat Emitters (CHEs) now from a local store so you can safely heat the tank while you wait for the other stuff to ship. It's best to research the setup prior to getting a new pet, so try to do as much reading as you can! And good luck!