GMM Program: Exercise Alternatives, 1RM, Repeating Program?

I am a beginner lifter/bodybuilder, but I prefer to use my home gym I’m making. First, in the GMM program, is there any substitute to the leg press and pulldown, or should I just skip them, or should I just go to my local public gym, or something else? Second, do you have any preferred way of finding 1RM on the exercises to base percentages on, or is just seeing how much you can do like a powerlifter the best option? Finally, can you do the program multiple times in a row, or after doing it once you need to find a new one for a while?

Thank you for your time

If you’re a true beginner that program is probably not best for you.

I suppose I’m not a “true” beginner; I’ve been lifting for about a year now

Would that still count as I shouldn’t do it?

A year = still beginner.

So yes, I wouldn’t look at that program.

Gotcha, thanks man