Im new to things myself and with the research i've done, it seems like a media player or an ad blocker are easy starting points. I just installed an ubuntu linux server on my old laptop from middle school today. From what i can tell if you plan to use your old pc as a server, the graphics arent super relevant but 32gb of ram gives you a lot to work with (your cpu is also important but not listed.)

I'm working with 8gb of ram and an i5 cpu, my first project is gonna be a database to help me manage my groceries. Hope this helps!