Hey worrier!
it makes a lot of sense to feel anxious about something new - and even more, something GOOD - working out. You already know to try to think positively about the whole thing, relationship aspects and all, but what kind of thinking patterns are you working with? Hypothetical scenarios? Remember that you're only responsible for your part of the interaction; try not to spend too much energy considering what other people think of your actions/words/behavior for the brief time (in the span of your life) that they've been with you. Instead, see if you can find any genuine connections with your new coworkers; those are always the easiest, least stressful, and most honest!