Yeah, if you're worried about the build and inexperienced, then you really do want to stick to slightly older, less cutting-edge platforms where more time has passed allowing most of the bugs to be ironed-out. If you do get stuck, there should be plenty of people who have had the same issue and therefore you're more likely to get useful results when running a web search for your problem.
There are lots of opinions here on what CPU you should get but that pair of videos
@R0H1T posted does point towards Ryzen being the best fit for you. In my own experience, the PCIe 4.0 of an AMD X570 motherboard and the stability and maturity of that platform (about a year old at this point) should make it a no-brainer for a video editing box.
The only tricky point for you to worry about is what RAM will work at optimum speeds on a Ryzen board. I think if you're worried, dropping down to a 3200MHz kit from Patriot, or GSkill will pretty much guarantee that you can run four sticks at the XMP speeds for easy, trouble-free RAM timings. If you want the best speeds that Ryzen can offer, then there are many forums and reviewers that seem to agree on the GSkill Trident-Z 3600 C16 (Q-64GTZNC) kit as one runs at 3600MHz on Zen2 without any problems, and 3600MHz is the sweet spot if you have a 3700X or better.
You have a large budget, but I honestly don't believe that spending all of it will get you any further than a $2000 build would. The 3700X and 3800X are almost identical, and I'd actually suggest getting the 3800X just because that is cherry-picked silicon that should have the best memory controller outside of a 3950X and is perfectly adequate for your needs. You're not going to be pushing overclocks on your RAM (not a good idea for a production machine) but the higher-quality silicon should just minimise the chances of getting an unlucky sample that can't run your RAM at the default timings you want.
I have access to 16-core and 32-core threadrippers at work, as well as 3900X and 3950X Ryzens. I've said it already but I'll repeat it in more depth: Buying a more expensive CPU will
not make a huge difference to Adobe Premiere, FL Studio, or gaming. The 2990WX render nodes I've built at work are barely half as fast again as my cheapo Ryzen 5 that cost me under £200, including VAT. That's 32 cores vs 6 cores, and $1800 vs $180. Save your money and buy something mainstream, easy to work with, and stable. I'd suggest the following and this is by no means authoritative or definitive, just what I would be buying if I put myself in your shoes:
- Ryzen 7 3800X. Ryzen 9 3900X is a solid choice if you see yourself wanting to do some 3D rendering in the future, but otherwise won't help your current software much.
- Popular, high-end X570 board like the Aorus Elite or Asus Croshair VIII. Technically MSI Tomahawk is superior but those two have better BIOSes in my opinion.
- Any 1TB SSD for your OS, applications, games. This one can even be a cheaper PCIe 3.0 x2 SSD as long as it's a TLC model like the WD SN550 and not a QLC model like the Intel 660P or Crucial P1.
- A fast NVMe drive for video projects. HP EX950 and Kingston KC2000 are both reviewed to have excellent sustained speeds ideal for large video files.
- A 2060Super; It is the cheapest 8GB/CUDA/Turing NVEnc card and it happens to be fantastic for gaming too. Sure, you can spend more, but it won't help your non-gaming at all.
) and it's a great AIO. It's actually my first-ever liquid cooling system. Had been using air coolers and finally decided to try an AIO for this 10700K. Couldn't be happier with it. 
