ForgeGradle

Expanding on this: If you intend for your capability to ever be used by other mods (i.e. you're making it part of your mod's API) then using an interface is very strongly advised, simply as good programming practice (expose the interface, not the implementation). If you only ever intend for your capability to be used for storing data for your own purposes, an interface is very much optional.  You might decide it's useful to have one, just for tidiness in your own code, but then again you're free just to use a class.  

Sere the bit below each of my messages that says "Reveal hidden contents"? Click on it.   This depends on whether you're talking about a mod or a modpack. If it's a mod you just drop the whole file in the mods folder. If it's a modpack, it depends on where the modpack is from, CurseForge modpacks need to be installed with either Twitch or Overwolf.

When putting mods in the mod folder do i need to "extract all" from the zipped folder for it to work, similar to how maps work?

I created a new directory for my forge profile and i'm going to see if that works. I'm new to the forums so i don't know how to "expand the spoiler"

Please provide debug.log (more info on where it is and how to provide it in my signature below, just expand the spoiler)