So I am terrible at creating worlds in CAW, so I haven't figured much stuff out yet. So if I sculpt the land a bit and add some hills and maybe a lake or two (if you can do that) and trees etc. Could I then put a 64x64 lot on top of it? Or would it give me the 'land is too uneven' thing when I try to place it like it does in game? I hope I'm making sense...I don't have very much experience in building.

I moved this to the CAW forum.

You can certainly place lots on hilly ground in CAW, there should be no problems with that.

The only reason for avoiding this is that, if you intend to leave the lot empty, it can be difficult for players to place library lots on an uneven base lot. You tend to get a huge dip or step on one side if you do this, and have to extensively resculpt the lot.

But if you are just building the world for your own use and intend to build a special building for that lot (a cliffside house or a tower for example), then it should be fine.

CAW should let you place lots anywhere as long as they are not too near an object, or another lot.

Thank you, this helped a lot!

Also, can I put in ponds/trees/other decorations in in CAW?

Yes- anything that should go into a world, you can place in CAW/EIG.

These tutorials may help:
Tutorials:TS3 CAW Tutorials^wiki

We also have a forum announcement and sticky posts that may help, too.