How long does it take for eBay to ship something?

Each item is different because you are not actually buying anything from eBay, the company.

Your purchase comes to you direct from the seller of the item that you are buying, so you need to check what that individual vendor says. If it isn't clear from the listing page, you can send them a message and ask for more details.

The length of time will depend where you live, where the item is shipped from (for example, the seller could be in a different country from you), also method of shipping that the seller uses to get your purchase to you.