Eating lunch alone the first week at a new job is just the waiting room before you find your people.

Eating by yourself in a new job is a stage rather than a verdict. The groups are already formed, the breaks are staggered, and nobody yet knows whether you are easy to talk to, all of which sorts itself out across a few weeks of ordinary shifts. It feels like rejection while being almost entirely a matter of timing.

Give the place a month before you decide anything about it. Sit near people instead of away from them and ask one small question about the work. Somebody takes the opening within a week or two, nearly always.