How do I use this store-made tomato paste with pasta?
Oh, that is not a real tomato sauce, this is mostly a tomato mush with a bit of salt. (The term "tomato paste" on the jar might a bit misleading, this product looks somewhat thinner.)

In a pinch, you can use it similar to a store-bought sauce by heating it gently in a separate pot on the stove (or in a microwave) and serving it with your spaghetti. But for a real sauce, it is probably too bland, missing spices and too acidic. Not what one expects from a sauce.

If you are really inexperienced, do a quick websearch for "easy tomato sauce" or similar. Many use tomato paste and you'll at least get a quick idea on how to use it, together with herbs and spices. In short, you want probably a bit of garlic, some herbs like basil (or even "italian seasoning"), possibly salt and pepper and - depending on the consistency of the tomato paste - a bit water (scoop a bit out of your pasta pot). If it's too acidic, add a pinch of sugar, not to make it sweet, just to balance out the acidity. Either toss the drained pasta in the sauce to coat or serve the sauce on top of the noodles.