I would find a provider with at least 1gbps port (depends on your poayer count), with some (30GB) space and few GB of RAM. But the main thing is bandwidth. I would be looking for providers with the cheapest traffic pricing / unlimited traffic
Doing it yourself is kinda involved… not for the inexperienced developer with an understanding of IT and coding. The Dev I used in the past did his CDN work using Kubernetes and I picked 2-3 servers - US/Europe/Australia to distribute our assets.
P.S.----
Not sure he still doing side-work, but it was Illenium that used to offer a commercial style CDN service. When he shut that down… I hired him to help me setup the 3 CDNs and I maintained it myself after the setup.