I added two torus objects, and when I click one of them, it also selects the other. They both share the same node thing. I want to delete one of them, but it keeps on deleting the other with it. I can't even undo placing the second torus without removing the other.
Go into edit mode and selecting the entire one torus by moving your mouse over the one and pressing L. Then press P which brings up a menu called separate, then just click on selection and it should separate them into two objects.
Go into edit mode, press P and press By loose parts.