Huh. I know a lot of people who did almost none of this and freelanced their way into successful businesses. Why is having an accountant necessary? Where I live, even simple books from the office supply store and basic tax software will tell you what you need to know as a beginner. Personally I operated my business just fine for 15 years without an accountant.
Drawing up a contract, similar, but here I would certainly mention that you can also consult a professional if needed, like a business consultant or attorney. You can also write a letter contract and communicate well enough that contracts don't matter that much in the end, which is the case for a lot of freelancers, guessing the majority.
Knowing what skill has high demand is less important than finding a team or business that likes you and needs you. If you are in tech, someone probably needs your help. Many times they will find a way for you to stick around anyway, if it's a good psychological complement.
If no one can pay you for three months worth of money, you get to decide how long you hang in there. Personally I found a veteran graphic designer who was excited to work together and started sending work immediately. Within 3 years of that I was turning down more work than I was accepting. But there was never any promise of income.
Setting aside 50% would have been impossible due to medical bills at the time. I was lucky to have free rent via the in-laws and a wife who was working as well. Still, when freelancing picked up the problem quickly became burnout and setting boundaries. This has been the same with many of my peers. Many of us went through 2008 and even the dot com crash together. Demand was never really a problem except at the very start, but the perception of an urgent need to hustle for every last client can easily break you.