Welcome to the forum, from another Pittsburgher (living in exile)!

When I bike commuted I used a small pannier to carry a change of clothes and my food for the day. Kept toiletries and dress shoes at work.

Consider the conditions on your route and think about whether you are visible to drivers, and outfit yourself appropriately with day-glo clothing, additional reflectors and lights. I have a screaming yellow PI vest that fits over a jersey or a more substantial jacket when it's wet/chilly.

Have fun!