Hi @LinkRVA, thanks for posting on the forum and welcome to the SimScale Community 
Our new users often compliment our introductory tutorials for their usefulness and share with us that running 2-3 of them before starting their own analysis tends to help in clearing things up. These two might be particularly relevant:
- Aerodynamic Flow Behavior Around a Vehicle Tutorial | SimScale
- Tutorial: Incompressible Flow around a Formula Student Car
By running these tutorials, you’ll notice that a first step in a CFD simulation is to generate a flow region, that is, a volume where the fluid would be. Take a look here for more information on this topic:
Cheers
Igor