How much FPS in Minecraft can you do on this PC and is there nothing left, so 8 GB of RAM is enough?

Sp
1

https://www.systemtreff.de/Basic-Gaming-PC-AMD-Ryzen-5-3400G-4x42GHz-8-GB-DDR4-2666Mhz-AMD-RX-Vega-11-Core-4GB-512GB-SSD

Sp

I would configure 16 GB (2x 8GB) Ram dad.