Opening BulkForged on your watch drops you straight into the Start Workout menu — pick a routine, resume something already underway, or pair for the first time.
If your watch is paired, the top row reports how fresh its data is: Up to date, Out of date (an older cache that'll refresh on its own), Sync failed (couldn't reach BulkForged — almost always Garmin Connect needing re-authorization), or Not synced yet (no successful sync since pairing). Selecting that row, or the placeholder row on a fresh install with nothing synced yet, retries the sync right away.
Below it, each of your routines shows its name and exercise count. Whichever one is scheduled for today, or was most recently started on your phone/desktop, is marked today or suggested so you know what the app expects next — though picking a different one is always fine. An off-plan Quick Workout started on another device never shows up here as something to start fresh; it only ever appears via Resume workout below, so you can't accidentally fork the phone's session.

Starting a routine here or on the phone reaches the same session — whichever device you finish on, the other one sees it happen live.
Related: "Pairing your watch to your account", "My Garmin watch stopped syncing — is BulkForged broken?", "Starting a workout off-plan (Quick Workout)".