I am definitely no expert ( only being doing it for 2 months) but i try to 1 hr per day for 5 days per week most of the time. But if busy only do 30 min sometimes. What are your goals? I train in my kitchen as I only want to perfect one arm pushup, handstand pushup, pistol squat and one arm chin up. Don’t really care for human flag or other exercises like that. Though I admit they are awesome and need great skill. I think getting there is half the fun so I doesn’t matter how long it takes to reach your goals as this will help drive you and be your motivation to keep fit.