One day in Corfu Town is plenty of time to see the main sights. You will be busy going from place to place, but you will have time to see everything. If you want to spend more time going shopping, relaxing at the beach, and soaking in the Greek culture, then two days might be better for you.
Does Corfu Old Town have a beach?
Corfu town has some beaches, but they are not as beautiful as the rest of Corfu. In the city centre there are two mini-beaches directly next to each other. They are very popular with the locals because they are never overcrowded. Faliraki Beach isn't really a beach at all.