I'm trying to build myself a house and I was wondering if it's possible to create a small pond with fish in the exterior cell? If yes, are there any tutorials I can look at?? I wasn't able to find anything...

Just look at the spawner references. Do a search for spawn...look for fish

And you can use any water source to put them in. Just search for water1024. Pick one of those.

In the CK go to the Tamriel Worldspace, then Falkreath. Then pan NW and downstream from that mill is a small camp with a pond and some fish. Those are the kinds of objects you can use to do so.

Alexander is correct, but be careful when searching other cells and worldspaces for assets. Maybe have a dirty esp file where you do this. With the esp you plan on making the home in though, I would urge that you pull objects from the search menu and nowhere else.

Thanks everybody