I got a spot in a web series that will begin shooting in a few weeks, but I've never done anything like this before. Generally, when you shoot a full length episode, do the actors have their script memorized fully as you would in theater, or do you just learn as you film?

You should get a call sheet beforehand that details what scenes they will film(or attempt to film) that day. You shouldn't have to memorize it all beforehand. You get very little "rehearsal" like in theater. There are also on-the-fly script changes so whatever you memorize may or may not be the same in the actual filming.

Ok, I figured it would be something like that. Just wanted to make sure. Thank you for your reply!