Changing ports isn’t a terrible thing, also not the perfect “fix” either, as you can still recognize open ports and scan the service on them.
Some ports are reserved in networking, so should stay away from those.
Some ISPs don’t allow you open ports on 80/443 as those are web hosting ports and they provide a service to consumers to download content from the internet, not for their consumer to be a web hosting provider as well. That’s at the residential level, if you have a business plan that might change, but it might be hard to convince and ISP otherwise.
It is doable to install an OS onto a flash drive or external drive, but from my experience it was really slow. Just need to make sure to then boot the machine to the USB device. Some machines you might find it difficult to change that in the BIOS.