I’m a 31 year old guy (5’9” and about 145 lbs) I’m pretty thin and I have a small appetite but I’ve been wanting to go to the gym and get back in shape (was in the army 8 years ago)

A few questions. Is working out 3 days a week good enough to see growth after a few months? I’d like to gain mass and not just lean muscle like when I was in the army from the workouts they made us do.

Will weed help? It definitely makes me eat more but I only get high once or twice a week. I know I’ll need to take in a lot of calories and protein.

I plan on getting a gym membership and workout with my friend on a Monday/Wednesday/Friday schedule for 1-1.5 hours each of those days and a different region of my body for each day.

What would you recommend for a beginner?