Does this Costco sell car batery

Yes

Yeah

Yes. Automotive service has them.

You'll need to check to see if your local store has a tire center. The batteries are usually sold in the tire center.

Yes, but they do not install them.

Yes, most Costco locations sell interstate brand batteries. Its probably a good idea to call ahead and make sure they have the model that fits your car stock.

Well... I'm sure that they do but im not 100% sure... But the best place I recommend you is to go to an auto zone or O'Reilly