Open a project

The space switcher at the top left is where projects live. It offers Recent Projects, Open New, New Sandbox and Remove project. Any directory works.

What happens the first time

Jensen indexes a project it has not seen before. An overlay on the map reads Scanning project, then Indexing graph. On a large repository this can take a while. jensen setup --no-scan skips it if you would rather index later.

Two things are left to you

Neither of these happens automatically, and both are deliberate.

The project is not trusted yet. A new repository stays restricted until you approve it. You can browse and edit a restricted workspace, but it cannot run project commands, local toolchains, debug adapters or plan acceptance checks. See Trust and permissions.
No assistant is chosen, unless exactly one is available. Jensen asks instead of picking. See Choosing an assistant.

Both are settled in the setup wizard, which is the next page.

Sandboxes

New Sandbox creates a throwaway workspace, for trying something without adding a project you will have to clean up later. It carries a dismissible notice saying what it is, and closes with Close Sandbox.

Removing a project

Remove project takes it out of the switcher. Stores for projects that no longer exist on disk are reclaimed separately, and workspaces holding traces, sessions or automation state are never removed.

See Storage and cleanup.