Comparisons
The real differences between two options, and how much they matter.
Creatine vs beta-alanine
Creatine, unless your event is an all-out effort lasting one to four minutes, where beta-alanine is the better buy.
Cutting vs body recomposition
Cut if you have a fair amount of fat to lose or want results sooner; recomp works best if you are new to lifting or returning after a break.
Free weights vs machines
Near enough the same for muscle and strength, so pick on what you will do consistently and what your gym actually has.
Full body vs split routine
Either works: with the same weekly sets per muscle, full body and split routines build similar muscle and strength.
Whey vs plant protein
Whey, by a small margin: in trials soy protein matched dairy protein for muscle gain, while other plant proteins did slightly worse.