1) I recommend a 3000 or 3200MHz 2x8GB DDR4 kit.
- Ryzen benefits up to roughly 3200MHz Dual Channel (google that if you want)
2) If you can increase the budget, you may want to get a 2560x1440, IPS monitor:
https://pcpartpicker.com/product/T8dFf7/dell-monitor-u2515h
(I bought that one for my sister. The Acer smidpx is $50 cheaper but Dell Warranty is way better)
The higher resolution makes a big difference for desktop, internet, and any game with smaller HUD/text (especially CIV5 and similar) though all games do benefit.
You can still choose the game resolution to use (i.e. 1920x1080) depending on whether that's best for the game. For example, SKYRIM SE plus some mods on a GTX1060 is probably best at 1920x1080.
Other:
a) CPU installation isn't too hard. Main points:
- be careful when placing CPU and tightening down the support that the CPU is in correctly
- use the "pea" method... just put about 5mm diameter ball of thermal paste in the middle of the CPU
b) update the motherboard BIOS
c) use MEMTEST86 prior to installing Windows www.memtest86.com
d) worry about CPU overclock and Memory optimization later (Ryzen memory is sometimes hard to get full speed)
e) during Windows 10 install:
- have your e-mail + password ready to use for Windows login (i.e. MSN account) as it asks likely (depending on how old the DVD is)
- PARTITION so you have 200GB for one partition and the remainder for another (at the start of W10 install... if stuck Google for how)
https://www.youtube.com/watch?v=HDgUrrmpRaU
Assign the 200GB (roughly 200,000MB) partition for Windows.
That allows you to CLONE to a 250GB SSD easily later. Install Steam like normal, but create a folder on the other partition (i.e. E:\Steam) and use that. It's all on the same HDD but again it's easier this way to add an SSD.