What is the correct timing when cooking spaghetti sauce from minced meat and prepared tomato sauce? First, after adding a little oil in the pot, when do I add the minced meat? Then how long do I leave it?

Also, when should I add the sauce? (I use a spaghetti sauce already prepared with all stuff in it.)

Finally: after I add the sauce, how long should I leave it before in the pot before I serve the minced meat sauce?
Add the meat when the oil is hot, then break it up with a spatula or wooden spoon. Cook it until it is completely browned. You may need to pour off quite a bit of liquid that comes out of the mince.

The jar of spaghetti sauce should tell you how long it needs to be cooked for.