It will work on pretty much anything that has a public IP and a domain pointing to that IP. The only thing that won’t work “out of the box” for most users is email, as most VPS providers block port 25. If you’ve requested access to port 25 and have been approved to use it, you can edit config.env to turn on the email service.
As for your SSL certificate, unfortunately this does not support importing your own certificate. It’s made for beginners, after all :p
But there should be no problems with Caddy simply requesting a new one for you!