Welcome to bike commuting -- fun, ain't it?
I like wearing mtb style shorts and a jersey because I sweat a lot so I never look tidy when I arrive after a bike ride. Never. If you have bike clothes already then you could always try mix of bike shorts under your work pants. Or wear a jersey or tshirt and pack your work shirt in the backpack (or even leave a few work shirts in the office it possible).
Wet wipes, small travel towel, clean socks, extra deodorant, and a comb is handy to leave at work to let you freshen up when you arrive. Unless your workplace has a shower and lockers -- then you're golden!
Have fun and don't forget, we like pictures of your commute.