(Personally, I'm probably above-average knowledgeable about fitness, but I still find the information unmanageably overwhelming - train every day, every 3 days, every muscle once a week, every muscle 3 times a week, big muscles less often than small muscles, focus on strength, focus on growth, focus on flexibility, cardio, no cardio, ...)
For generic "get fit" goals, stretch every day and some amount of cardio/resistance training three times a week is hard to get wrong. The important thing is to read your body and don't push your luck. Also, to stop when you lose good form.
There is a lot of overwhelming information, but a lot of it is conflicting and anecdotal. You yourself point out - should you go for growth? 5 days on? 7 days on?? You can find information online to support pretty much any theory you like (particularly about training frequency).
Body composition changes typically go through multiple different phases and cycles. It might seem like you'd want someone specific for each phase, yet some consistency is helpful across phases too. As an analogy, you wouldn't want to change universities for each year of your degree
I'm in the process of building the largest online fitness database of its kind to democratize a lot of this information. I'm not sure what sort of business model I will pursue yet. But I want to collaborate with likeminded people and make the foundational information open to the public.
Eventually you'll have to learn through experimentation what works for you. Will take 5 to 10 years.
I like Jeff. He gives great advice. But in the same way a dictionary isn't a great place to start with reading.
I'm semantically analyzing/connecting Jeffs videos for my database.