Hi I'm trying to get into Freelance Motion Design professionally what are some tips can the community offer me as a newbie?

[Alonzo Nelson 0]

Hi my name is Alonzo Nelson. I'm trying to start up my career as a freelance Motion Designer/Video Editor. I've been doing mostly local video editing work here in NYC using Premiere Pro CC 2018/19 but it was not on a professional level just on a "handshake" deal with no contracts or invoices and I want to start making myself into a professional Motion Graphics Designer. I use mostly After Effects & Premiere Pro (both 2018/19) for the projects and gigs I get. My goal by the end of 2019 is to have a website showcasing my work, a demo reel (with mostly internet tutorials lol) and a social media presence to market myself.

I'm in the real early beginning stages of this endeavor I've been doing a lot of research this month watching Roberto Blake videos on YouTube, taking notes on how to start a side business, reading blogs on PremiumBeat & Motion Array, etc. I have a primary job with a hectic schedule, I don't get paid much but I do have health, dental & a 401K so that's not an issue. My goal is to start off small with a steady amount of clients and when I feel the business is in a good position I can reduce my hours at my regular job and put in more hours on this. My first priority is to buy a new work station STRICTLY for the purpose of creative work. I like the Apple ecosystem so I prefer to stay in that lane and not go PC. Here are the specs on my current work station:

13-inch, Mid 2012 MacBook Pro
2.5 GHz Intel Core i5
16 GB 1600 MHz DDR3
Intel HD Graphics 4000 1536 MB
1 TB SSD storage

I've been doing some research on the Mac Mini 2018 over the last 2 weeks and I'm looking to buy it in the future. I use most of the programs in Adobe Creative Cloud but I mainly use After Effects 2018/19 & Premiere Pro 2018/19 is a close second. Here are the specs I want to get for the Mac Mini 2018:

3.2GHz 6‑core 8th‑generation Intel Core i7 (Turbo Boost up to 4.6GHz)
8GB 2666MHz DDR4
Intel UHD Graphics 630
1TB SSD storage
10 Gigabit Ethernet

What do you think? Is this enough for a guy like me who is saving money and just getting started trying to become a professional Motion Designer/Video Editor?
Also how much do I start charging since I'm just starting out? 
Revisions? Even though I was doing local video editing work unprofessionally how do I determine how much revisions is too much?
Do I charge a flat rate or hourly?
Contracts, Invoices, Taxes, business bank accounts, etc

I have so many questions and did a lot of research up to this point I'm nervous & excited to start this journey but I want to do it right any advice for me?

Thanks in advance to reading this long message...

[me2please 0]

Do you have a body of work yet? The freelancers I hire, I hire based off of their reel. I feel like your work is the price of entry. For example, if you go to my  Utah Video Productions website you can see the type of work I do. What I'm getting at is, if someone was looking for a company in Utah that did Video work and they landed on my site they could see. If what I do isn't the type of work they are looking for chances are they would move along.