I recommend Fedora if you want a clean installation. That is, no non-free software. It might be safer than Debian or Ubuntu, might not. But I use it.

All of the "free" (as in free beer) Linux distributions go out of support quickly. You need to replace the OS about once a year (or maybe slightly slower).

The "free" (as in free speech) distributions let you run much longer with support. Red Hat is probably the best known, and I would recommend it if you don't mind paying for your OS.

Red Hat is cheaper than Windows Server, but more expensive than the Windows Home Server product.

Windows Home Server may be just what you want.