Put an ice cube, 2 tablespoons of flour and 3/4 cup of water in a small container with lid. Shake vigorously until well mixed. Add to your pan drippings which have had most of the fat skimmed off. (A turkey breast won't have much to begin with so you may not even have to do this). You can also add the liquid from any vegetable you may have cooked or a small amount of vegetable stock (maybe 1 cup) to the drippings in the pan or if you have nothing on hand add some water. Heat on medium heat until it bubbles a bit for about a minute or two then turn the heat to low, while stirring with a whisk to keep it from being lumpy. You can season it with salt pepper, Seasonall salt mix, or whatever seasoning you like, just don't over do it as you don't need a whole lot.
One of my easy tricks is to add liquid to the pan right after I take the cooked turkey breast out of the oven, as this deglazes the flavor bits in the pan almost immediately. This also assumes you have some little brown bits in the roasting pan. I'm trying to cover all the bases here.
You can get fancy and add other things such as finely chopped onion or parsley or whatever gives a flavor you enjoy.
Gravy is not really rocket science and is really just a fat and a thickening agent (flour or corn starch) cooked together and then thinned out with a liquid and seasoned to taste. You can do it. Nothing tastes worse to me than canned or bottled gravy, and I also didn't really like Costco's gravy package that my older daughter purchased last year, but we had a lot of turkey so it helped out. As far as flour versus corn starch - corn starch doesn't lump as much and cooks quickly but flour tastes better.
And edited to add: that giblet package goes straight into the trash. Except for the neck which I will roast with the turkey for seasoning the gravy. It's bony and bone = flavor.