Go to your LBS(s) and get something that fits...avoid the temptation to save a few bucks on the internet until you have some experience on how things fit.
MTB shoes with SPD pedals are a good way to be clipless and be able to walk with minimal issues...Shimano makes a cleat that breaks out easily/either way for those of us less coordinated.
Buy a good/bright red strobe for the rear of your bike...a white for the front would be good as well, but are sometimes pricey.