Could I make cheese sauce out of?

Yep. Melt 2 tbsp of butter, stir in 1 tbsp of flour on medium for one minute, then add 1 cup 1/2 of milk. Slowly heat it and add your cheese and stir it till it melts smoothly. Add whatever spices you want, or extras like bacon (cooked).

You say you have "sliced cheese" do you mean American cheese?

If that is the case, you don't actually need to do the flour. A flour rue is only needed for cheeses like cheddar, which separate from the oils when you melt it down.

Sliced American cheese can simply be cut into cubes and melted over low heat.

For an 8Oz. Package of American cheese, I suggest starting with a 1/4 cup of milk.

Stir it constantly to prevent burning.

You can add extra milk 1 tablespoon at a time if you want it thinner.

Yes, of course you can make it out of that. However, I just noticed that you didn't mention any kind of noodles. You can use any kind of noodles, they don't really have to be macaroni or shells. Then just put a little bit of water, and some milk in with the completed pasta. As that warms up, cut the cheese into small pieces and put them in the pan. Just keep stirring until the cheese starts to melt. If you have any butter, add a little of that, too. When milk and melted cheese thicken in the pasta , you're done.

First you need to make a rue which is just flour and butter, then add some milk. Once you did that you can add the cheese. You make the white sauce first the. Add the cheese so the cheese won't burn. Then you can add it to the pasta and put it in the oven. Hope this helps. Good luck:)