Two days in Siem Reap, Cambodia?

I'm going to Siem Reap next week and just canceled my tour booking due to unforeseen budget cirstances. I heard that you do not necessarily need a guide to go to the Angkor temples, is that true? I'm planning to just hop on my bicycle and cycle around town on day 1, venturing their markets and catch a cultural dance over dinner and day 2 probably hire a full day driver and see Angkor.