Going to sell merch for an organization- new to this and overwhelmed. Site suggestions?

I unknowingly volunteered to start a merchandise store for an organization I used to volunteer with, and know nothing about all this. I need a site where I can throw the logo on products; a drag and drop to design sort of thing, and place that ships to both Europe and US (or, just Europe would be acceptable). It looked like Teespring might be the easiest option, but was wondering if anyone had suggestions. Thanks!