It’s summer internship time, and you landed an awesome gig for the season at a cool new startup. Congratulations! Now for the bad news: you’ve just gotten yourself invited to the longest interview known to man. Huh? Well, if you are like most interns, you are looking for one or more of the following from your internship: connections, mentorship, or a full time offer at the end of the summer. To maximize your chances of getting any of those three, you’ve got to be in top form the whole time. And first impressions are both important and lasting.

Think about it: No entrepreneur is going to introduce you to anyone significant unless they feel you’re going to impress their friends as well. No entrepreneur is going to take time out of his or her insanely busy day to give you real from-the-heart training unless they feel vested in you. No entrepreneur is going to want you to come back full time unless, obviously, you’re heads and shoulders above the other candidates that inevitably will be competing for the full time offer.

So with that being said, here are some suggestions for having the best possible first day on the job:

• Bring a smile. In startup-land, a positive attitude is absolutely essential 110% of the time. Working at a startup can be like being an actor in Hollywood – you’ve always got to be exuding uber-confidence in yourself and your business. Your colleagues are going to want to see that whatever chips may fall, you’re going to maintain your sunny disposition.

• Be smart, but not a know-it-all. You got the job – you’d better have done your research on the company, its competitors, and its target market ahead of time. But no one needs an intern to come in with suggestions on new products or marketing techniques. Don’t be a show-off – if you’ve done your research, it will show in conversation. Tip: you don’t need to do this in a vacuum. It’s completely OK to ask for whatever company information, presentations, etc., from the company ahead of time.

• Meet with your boss as soon as possible. You might be waiting for your superior to schedule your day for you, and you might assume that your first day will be lined up with training sessions and meet-and-greets with the entire office. If that is the case, awesome. The more likely scenario in a startup is that they’re not that organized, and they haven’t planned for your arrival – or that they did plan, but a huge client meeting came up that threw the entire day off course. Make sure that if this happens, you at least get a meeting, coffee or lunch in with your direct boss first thing. And in that meeting, get some direction on how he/she wants you to spend your days, and whether there is a short- or long-term deliverable you should be working towards. That way, even if you end up a bit in limbo on Day One, you’ll have something to focus on when you get to your desk. Tip: email your boss the night before to confirm a time to meet.

• Don’t be first out the door, but don’t be last. This is going to likely be a summer of a lot of hard work. The truth is that on your first day, they’re probably not going to overload you with a ton of to-do’s. But ringing the bell at 5 pm on the dot is going to offend your co-workers. Find a happy balance and watch your colleagues for the cue when it’s an appropriate time to leave. Tip: ask a few people out after work that night – not only will you get to know some folks better, but that way you’ll be leaving in a group.

The first day on the job can seem daunting, even for seasoned professionals. Hopefully this advice can help ease those day one jitters.