I built a couple of Vega projects back in the early eighties. As previously stated. Not a task for a novice.
At the time, most Vega type cars were disposable so it made for an inexpensive project start. But the costs/labor of a V-8 streetable car are large.
Needs custom headers, exhaust, radiator and rear end. Fabbed mounts. Better brakes/suspension all around.
Probably best to sell body as a Drag car project and buy a Mustang, Camaro or G-body something and build from there. Less fab/custom $$$$ mostly bolt on stuff and readily available parts..Lots of support.