I'm new to foundry and is trying to build a forward base with shuttle pad, but I can't find any shuttles.

I am talking about the high-detailed and well modeled ones you see on ground maps, like the rescue shuttles from Mine Trap.

Do they have it as a placeable prop in foundry or did I just over looked it?

The shuttles are in there. Runabout is not.

What menu is it under?
Is it just named shuttle?

Its under the details tab, I think it is just called "Shuttle"

Also there is an interior with a runabout built in. Can't remember the name, but its one of the Federation interiors.

Argelius II has one. But it's in a hangar bay that's relatively small.