for beginners, learn the proper posture or suffer back pain for the rest of your life.
Better yet, just start with military press, bench press, pullups and dips. Two of those combined in a single day are already hell for the shoulders. No need to isolate for the newbies and non-injured.
Beginners must learn to stick with compounds and when they can finally squat double their body weight, that's the time when they should assess if they really need isolation exercises.