[lohmos]

I have some PS/2 to USB connectors I was trying to use with a USB keyboard and mouse but obviously I can't tell if it's working without being able to see anything.

Those adapters did not work for me on my O2 so get an ps2 mouse and keyboard, a vga-able screen (or an adapter dvi, hdmi, whatever) and if necessary boot the installation tools and overlays cd 1 (archive.org) and set a new password if you cannot login or use the demos or guest login.
You should be able to open SoftwareManager (swmgr) as non-root too, just to see what's installed there.

Other possibilities are to use telnet (after an ipscan) or a terminal 9800/8/N/1

it is not so complicated - if you have some questions ask here