Wear a (work-appropriate) outfit you really like. When you’re comfortable and you know you look good, everything is just a little bit easier.
Plan to be at least 20 minutes early on your first day. Yes, that sounds like a lot, but chances are, you’ve never had this exact commute before, so it’s better to leave too much time than too little. Plus, it’ll give you a few extra minutes to collect your thoughts and remind yourself that you’re gonna be a great employee.
Pack a lunch as a back-up. Ideally, you’d want to go out for lunch with your boss and/or co-workers on your first day, but it might not be that kind of workplace. So pack a lunch just in case your new workplace isn’t a go-out-to-lunch kind of place. After all, it’s better to have a lunch you don’t need than to need a lunch you don’t have.
Bring a notebook and a pen, and take lots of notes. You’ll be learning a lot these first few days, and it’s probably a little unrealistic to expect to remember it all perfectly. So don’t! Instead, take notes on all the important stuff: procedures, supply locations, who reports to whom, what to do if something goes wrong and where the bathroom is.
Always think “customer service,” even if you’re not in customer service. If you ever encounter a customer of your company, treat them as if they were a beloved relative: with kindness, politeness and lots of listening. If your position doesn’t involve interaction with outside folks, remember you’ve still got customers: the co-workers and managers for whom you produce your work. Make their lives easier, and they’ll be inclined to make yours easier, too.