How do I get out of the basement?

Well, if you brough the right item, you could attempt your make your way out.

Try to cut the bar with the hacksaw from your house.  If you don't have it,
you'll have to restore and get it.

This will trigger the weirdo to give you his knife.

Look at the knife, and notice all of the gadgets.

Press the button.

Then, pull the lever.

See that the knife has a built-in power saw?

All you need is some power.

Plug the saw into the generator that popped out of the knife.

You can't use the generator and cut the door open at the same time.

So try to make the weirdo useful.

Give the saw to him, while you sit on the generator.