Can't install O.S.

Hello everyone,
I'm in need of help with a recently assembled computer. My problem is that it seems I can't install any O.S. on it because it gets stuck/in loop/don't get recognized, but the bios runs and I can operate with it. Also, I have some annoying horizontal red lines going all through the screen while I am in the bios: sometimes are few, sometimes they paint my whole screen red.

I tried to install:
- Debian: gets stuck or goes in loop after selecting a menu (intall or run live) and returns to the selection menu
- Linux Mint: same as Debian
- Windows 10: doesn't even get recognized

Here's the specs of my computer:
CPU      AMD Ryzen 3 3200G (with Radeon Vega 8 Graphics)
GPU      Integrata nella CPU
Mobo      ASRock A320M-HDV R4.0
RAM      QUMOX 4GB DDR4 2133MHz
SSD      Transcend SSD230S 128GB
PSU      Tacens APII500 Anima - 500W

And here what I've already tried to do:
- changed the CPU+GPU with another one
- changed vga and hdmi cable (tried both
- tried with a different monitor
- tried with a different PSU
- moved ram on the other channel
- disabled UEFI and run legacy USB

None of that solved it and I sincerely have no idea what to do. Can someone please help me?
Thanks in advance