official "tutorial" (light but it was enough for me) here : https://github.com/laurent22/joplin/tree/dev/packages/server.
A more comprehensive one is here but not supported and initially for raspberry so you would have to adjust some things to your context : Guide for Joplin-Server on Raspberry Pi.
I'm not sure you can install it on a shared host because you need docker and/or npm/xxxxxx. You should instead use a dedicated server online for example.