Configure computers for games and work

I have a Graka 3070 Tuf Gaming (ordered and paid for, according to Saturn, coming January 12)
I haven’t had a computer for 10 years, and now I want to set up a desk and also built a pronto facility for a 9 square meter office. https://www.froschkoenig24.de/buero…nverstellbaren-schreibtisch-lichtgrau/a-34745
The other room is 2.2 x 4 meters or so and the desk is at the end of the room by the window.
The printer is also available. That’s all.

I don’t want to know everything about all of the ingredients. So I wouldn’t read about the topic of RAM, for example.
I just take what is suggested.

1. Do you want to play on PC? If yes, then what?
PUBG, Battlefield, Football Manager, Cyberpunk (if new games like Fallout appear), and the like
WQHD will be very good, because graphics are there.

2. Would you like to use the computer to edit photos / music / videos or the like? As a hobby or are you a professional? What programs will you use?
No

3. Do you have any special requirements or desires (overclocking, particularly quiet computer, RGB lighting, …)?
No condition, it can be loud. (Heats the neighbor strongly, so the room is always very warm. But I like the colorless mix very much. So visually more monochromatic (can also set RGB))

4. How and how many screens do you want to use? Model, resolution, refresh rate (hertz)? Gsync / FreeSync?
1 Screen Here’s the question, how important is it that the display has Gsync on the 3070?
27 inches is ideal, and more is possible, too. I thought of one here: Monster Aryand a32, because it’s cheap and everything is available.

5. Do you still have an old computer, some of its components can still be used?
(Please with links or names of exact models)
No

6. How much money do you want to spend?
Difficult question:
Processor 300-500 depending on recommendation (think Ryzen 5600)
1 TB hard drive, think the Samsung 970 (which costs around 129 everywhere)
Monitor up to 400 if possible
Mouse and Keyboard 150 ideas from Razer ornata and Viper because I have a small hand.
I also gladly accept mouse pad ideas
Headphone (should help me make sounds by making it easy to hear the steps in the game, for example through software)
An office chair and not a gaming chair (ugly)
Motherboard MSI Wifi Carbon 550 or whatever it’s called

Money there

7. When should I purchase a personal computer?
Immediately, I want to order right away, no matter where.

8. Do you want to assemble the computer yourself or assemble it (from the store or helpers (list it as a sticker))?
Coworker does it

9. Want to broadcast to a computer? If so – what are the games / content? Do you already have parts for setting up the stream? (Multiple monitors, microphone, camera, transmitter, …)?
It doesn’t broadcast, but Skype could be important in the future, as I recommend building leases and doing it very successfully over the phone.

Still important to know. I’m a humble player, so I want at least the best equipment so I don’t stop completely.
I’m only 170 cm tall. (Because of the chair and headphone).

I wrote on a forum, be nice to me.

Summarization. Complete equipment including chair and accessories for a little man who wants to become a gamer