Beginners,doing multiple modifications at once......

Good advice.

I still think myself as beginer at car repair/modifications after 3 years.

But always safe way to start build is stop, steer and go.
make sure all brakes etc are in good shape, then steering/handling, nothing fancy, new bushings etc.
Rust repairs are good to do at some time:)

After that you can think about making car go:)