I'm only 14 years old and I'm looking to buy a PC over the summer with a $800 budget in mind, all i really need is just to run stable 60 FPS on highest possible quality with 5 cars. my current list for parts as a simplified list is: CPU: AMD Ryzen 3 1200. $100 Motherboard: Biostar X370GTN Mini ITX Motherboard. $110 GPU: Used GTX 970. ~$180 Thermal compound: MX4 arctic thermal paste. $4.40 RAM: Crucial 2400 MHz DDR4 8gb memory. $84 SSD: Samsung 850 EVO 250 GB SSD. $90 HDD: Seagate Barracuda 2TB 5400RPM Hard drive. Power supply: Silverstone Bronze 80+ certified Bronze power supply. Case: Fractal design Node 202. $80 case fans: (x2) Arctic 120mm fans: $4.20 (each) From past experiences i know that beamng drive can be very CPU intensive with lots of cars. so i might upgrade to a Ryzen 5 1400 in the future if the Ryzen 3 1200 bottlenecks my GPU.
For $800 (USD) you can get better. Maybe a R5 1600 + GTX 1060 (6GB not the 3GB) will do. Downgrade the board to a B350, a X370 isn't that much a better choice, since both can overclock well.