How do I set a default folder so that the Komodo Editor opens with the folder I want to work with?
I think you’re searching for projects, Komodo also has a function to restore the last workspace (this will restore the file you had last open).
But when you go working with projects each project has a default (remote) folder, when you open the project it will open the project files location.
Some more information about using projects can be found here.