Can't uninstall Manjaro and install Debian

So, I was using linux distributions for 6 months. I tried Ubuntu, Zorin OS, Deepin, PureOS… This week I tried Manjaro Xfce. I installed it and use it for maybe 2 days and I it’s not my cup of tea. I put Debian on bootable usb and try to install it like every time. I tried UEFI in BIOS and thats give me nothing. When I go on Legacy that only brings me black screen with one underline. Can anybody help me please?

Did you use a known to be working installation source for the installation of Debian?
Are you sure the medium was written correctly?
and if so: how?