Where to store custom packages?

New to Julia
3

Hi again Fredrik.
I tried to develop my own package from my working directory, but it does not work:

(v1.1) pkg> develop C:/Users/sindre.abrahamsen/juliafiler
[ Info: Assigning UUID df5de59a-cb49-5d19-96de-9b3899e6645c to juliafiler
 Resolving package versions...
  Updating `C:\Users\sindre.abrahamsen\.julia\environments\v1.1\Project.toml`
 [no changes]
  Updating `C:\Users\sindre.abrahamsen\.julia\environments\v1.1\Manifest.toml`
 [no changes]

julia> using MyModule
ERROR: ArgumentError: Package MyModule not found in current path:
- Run `import Pkg; Pkg.add("MyModule")` to install the MyModule package.

julia> import Pkg

(v1.1) pkg> add MyModule
ERROR: The following package names could not be resolved:
 * MyModule (not found in project, manifest or registry)
Please specify by known `name=uuid`.