All grain is pretty imposing for the first time brewer, I really suggest a few extract batches first.
Thing is once the wort (beer before fermenting) is in the fermenter the process remains the same from then on out.
The keg would be for boiling the wort (or a giant ass canning pot)
Carboy isnt needed at first, buckets are fine.
You'd be bottling at first
Kegging can get $$ but you can gather stuff over time.