Welcome and thank you for posting!
Because everyone's transition experience is so unique, there's no be-all transition guide that I can refer you to. But I do recommend reading this:
Medical Therapy and Health Maintenance for Transgender Men: A Guide For Health Care Providers
The place to start would probably be your doctor. Do you have one that you trust? Trans-knowledgeable is helpful but not required. Typically, a doctor refers you to an endocrinologist (endo), assuming you want hormone therapy. Your doctor can also provide referrals to surgeons, if you live somewhere that has surgery funding in place. If you are paying out of pocket for surgeries, then you can make arrangements directly with the surgeons' office.
Surgeons will require letters of support, usually from a therapist of some kind. Finding a good therapist is another building block that you can work on now to move things forward.
When to use the men's room is a personal decision. I didn't feel safe enough to do that until I'd been on hormones for a bit. Also, depending on where you live it could be against the law for you to use the men's room if your ID says F. I would probably hold off a bit.
I hope this helps! Please feel free to ask anything.