I just started with modelbuilding so this is my first model ever... It's probably very bad but hey it's a start

It's the Tamiya Flakpanzer Gepard 1/35


I painted the model with Tamiya olive drab paint and used a brush. I'm thinking about doing some effects or something but don't know what to do exactly... Do you guys have some tips and tricks? And another question do you normally paint a base coat first or something?
Greets,
Bob