Just acquired a used 20 gallon aquarium, questions on set-up

Hey r/aquariums I was just given a 20 gallon aquarium from a friend. It was drained about 5 days ago. I am assuming I should clean it and start to cycle it since it has been dry for a few days? Is that the best way to get started? The filter and lid have some build up on them. Should I clean them off before refilling and setting up? I am right to assume all the good bacteria etc is dead now since it has been dry for a few days? Should I put new filters in or use the old ones that came with it? Thanks and excited to get a new tank set up again!