Where do I start?

I just got laid off from my company and have all the time in the world. I have been selling on Amazon for a while now via FBA at a very MINISCULE level but some of my friends tell me with the time I have on my hands I can begin with FBM/MFN. The reason I did not start this earlier is because on my original Amazon account which I conduct FBA on – My FBM rights are disabled due to a few violations. I am thinking I should grab PO box address and start fresh from a clean slate (because i cant have two amazon stores on one address). I am looking to learn more about the business but every time I try looking for something I get hit with a “guru” that is looking to sell a course. I have learned minor ins and outs about the FBM model but I am still on my way of learning more. What would be the best place to start? My friends suggest to just start and figure things out as I go, however with no income coming in on my end I am proceeding with caution. Any advice helps.