TortoiseGit doesn't add files automatically

Make sure the Show Unversioned Files is checked. See:

For your second problem, go Settings/Git/Credential and try to use manager helper. Also see A: TortoiseGit save user authentication / credentials

Make sure you don't have a rule in your .gitignore file that might be excluding files unexpectedly. For example here I have localhost.pfx set to be ignored but the right-click context menu still allows me to add it to a commit:

On similar issue:

I wanted the Windows Explorer to show git folder as changed (red color) when a new file is added.

Below worked:

> Tortoise > Settings > Icon Overlays
  > check the box "Unversioned files mark parent folder as modified"
  > Apply & OK
> Restart computer (since it is explorer extension it is not working without restart)

Hope that helps.