While a pen and my scientific calculator (engineer here) is what I usually bring to my first day of work, I'd say, bring your bests from the first day forward. Bring you best smiles, for other co-workers to warm up to you. Bring your best outlook for this job, bring your longest patience, so that you'll have plenty of time learning how to best do your new job. In short, bring your best self from day one to the future ahead. Changes sometimes put people in a chaotic mood. For the new worker and for the group that you'll about to be working with, so it's best to always be optimistic and positive in approaching new phase of your working life. Bringing your best self at your first day of work really puts a big and lasting impression on you so one should always set that bar on a good note.