Java Edition is the Edition people use and create mods for, not Bedrock (Console, Phones, Windows 10), if you want tutorials for modding on Forge or Fabric try documentation (like wikis), forums or Youtube videos I can recommend some.
I can't say for servers or hardware that is suitable but the video above and those on forums/Discord servers can help with setting up modded servers if need be. I only know that with Forge you would need to install server instead of client with the installer and putting mods in the server folder, can't say for Fabric.
In terms of which version to go with, I'd say it depends on what modloader and what versions they support when making mods, but when playing with mods what version can be determined by the volume and the types. 1.14.4 is the more recent (not counting 1.15 as it's too new and many mods are getting use to porting and documentation for it while similar to 1.14 for both Forge & Fabric, I'd still recommend earlier) but 1.12.2 is more popular and has many that could be asked for assistance with. Modloaders change based on either what Mojang does to the game or what the Modloader team decides to do, so keep that in mind (which 1.13+ changed a lot due to how Mojang changed the game and because the Forge team wanted to make their own changes). Some versions like 1.7.10 have people still developing for it either because they want to, the community is still there, hardware reasons if they haven't upgraded their computers (or are comfortable with 1.7.10 in general) or because 1.8+ modding changed a lot and those that develop for 1.7.10 do because of the changes to Forge.
I'd start with a singleplayer world and LAN first then move to servers if need be.
Some sources I recommend for modding/datapacks are these:
https://discord.gg/v6v4pMv (got to the #mod dev or #player support channels to get assistance with developing mods or setting up a Fabric server)