Hi OepnBSD has its own installation system. The operating system itself has a steep learning curve for a beginner. I'd suggest you start by reading the relevant parts of the faq https://www.openbsd.org/faq/index.html and the installation notes https://ftp.openbsd.org/pub/OpenBSD/6.6/amd64/INSTALL.amd64
I run a similar amd64 myself and can now install the base system in about 4 minutes from the install iso https://ftp.openbsd.org/pub/OpenBSD/6.6/amd64/install66.iso It will install to a usb drive. Good Luck
