For five days a week, I do an upper-lower split. I tend to do lower body Monday, Thursday and Saturday, and upper body Tuesday and Thursday, taking Wednesday and Sunday off (I may do cardio stuff those days).

My priority at the moment is legs, due to a bad knee which I’m focused on keeping stable and strong. You could switch this to having three upper days per week with two lower, if you’re more focused on upper body growth. Or you could even do a push-pull-legs, but then you’d only maybe hit legs once a week, which I think is too little personally - again, all depends on your goals.

With any split, you can easily find a free starter program if you look around. Then you can tweak it based on your own needs. As an example of the content: for my upper days I focus on hitting upper back, lats, some lower back, chest, front, side, rear delts, as well as biceps and triceps. And I add abs at the end. For lower body days I do glutes, quads, hamstrings, calves, adductors and abductors. Sometime o add abs on leg days too.

Which exercises you specifically want to do for each muscle is really down to preference. If you’re very new to it, you could start off with machines, and over time you can tweak your programme to be more varied e.g. with free weight, cables etc. The main thing at first is to learn the form of each exercise, and to track your reps and weights, so you and progressively increase those over time, for growth.