I wouldn't automatically rule out bottled sauces. They are not my first choice, since rarely do bottled (or canned) sauces come up to the quality of freshly made sauces, no matter the quality of ingredients and care that go into making the bottled or canned sauces. To the extent they are used, however, I would select those that are simple, like a basic tomato-basil sauce or a marinara sauce, or possibly a sun-dried tomato sauce. These sauces, and especially those that do not have a lot of tomato paste (which will often be the first item listed in the ingredients label), make a nice base for pizzas and it is possible to build upon them by adding other ingredients, like garlic, herbs, onions, olive oil, cheese, etc. Again, these are matters of personal preference and taste.
As a cautionary note, I would tend to avoid those prepared sauces that are overly heavy on the use of sugar, usually in the form of dextrose, or corn syrup (the cheapest industrial form of sugar). The heavy use of sugar is an indication that the tomatoes used are not of the highest quality and require the sugar to compensate for the lesser quality (usually to overcome sourness or acidity). Even these sauces can be improved, by combining them with good tomatoes, such as crushed San Marzano tomatoes, if you have them, or even fresh tomatoes. Among the more notable brands of prepared sauces I have tested and found acceptable when I am too lazy or unable for some reason to make my own are Ceriello's, Muir Glen, Rao's, Timpone's (Mom's), Lidia's, Cucina Antica, Michael Angelo's, Colavita, and, among the major supermarket brands, the Classico brand. In general, I look for the sauces with the shortest ingredient lists and the fewest chemicals with strange or unpronounceable names. You will find that, with the exception of the Classico brand, the best bottled sauces are not particularly cheap. Making your own sauces will, in most cases, be cheaper and better, even with the somewhat higher cost of the tomatoes (like the 6-in-1s, Stanislaus or San Marzanos) you decide to use.
As for the use of pizza screens, the first thing you may want to check is whether the 18" screen you just ordered will fit your oven. Most home ovens won't take more than about 16-17" with the oven door closed. I use both screens and pizza stones, which I use both individually and in combination. The biggest disadvantage I have found in using pizza stones is that they can't accommodate the larger pizza sizes, that is, above 14 inches (although some round stones can handle 15 inches). This can be overcome by ordering a custom stone design, but that is quite expensive. It is far cheaper to use a pizza screen for the large pizzas or just tile one of your oven trays with a bunch of tiles from Home Depot or Lowes. There is an enormous amount of information at this site on screens, stones and tiles, and their relative merits and demerits, and I suggest that you use the site's Search feature to access the postings on those topics. This will make you an instant expert
I will leave to Giovanni, our resident expert on freezing pizza dough
, to answer your question on how to prepare your dough for freezing. Remember, however, that freezing the dough as Giovanni has done is a short-duration exercise prior to putting the dough into the refrigerator section of the refrigerator.