Push
Chest, shoulders and triceps
Split your training by movement pattern: push, pull and legs. It is one of the most popular routines for building muscle once you have the basics down.

Each session focuses on one type of movement. Push day trains chest, shoulders and triceps; pull day, back and biceps; and leg day, quads, hamstrings, glutes and calves.
Grouping muscles that work together lets you do more volume per muscle in each session and recover while you train the others.
Tap any exercise to see its technique and common mistakes.
Chest, shoulders and triceps
Back and biceps
Quads, hamstrings, glutes and calves
If you choose 6 days, you can use variations in the second round of the week (for example incline barbell press instead of bench press).
On the main lifts (bench press, pull-ups, squat) try to add weight or reps every week while keeping good form. Rest 2-3 minutes on them and 60-90 seconds on accessories.
Every 6-8 weeks, if fatigue builds up, take a deload week by cutting the sets in half.
It can work, but in the first months a 3-day full body routine is usually better because you repeat each exercise more often and learn technique sooner. Move to PPL once you progress steadily.
With 6 days you train each muscle twice a week, which usually gives better results for muscle growth. If you can only go 3 days, the 3-day version works, but consider an upper/lower or full body routine to keep that frequency.
Add 2-3 sets of a core exercise (plank, ab wheel or cable crunch) at the end of 2 or 3 sessions per week.