Use the Celebrity shuttle to get into town. Defintely do this, it is only $7 a person and the walk is not worth it. The town is a glorious postcard. There is really no need to book an excursion for this town, just go into town and enjoy it. It will be exactly what you hoped for.
Best excursion of the trip!! Take the boat tour NOT the bus. The boat tour gives you a beautiful boat ride to the town of Amalfi, where you have time to get off and wander the town, shop and have some gelato. Then back on the back where a bus take you on a short ride to a castle on a cliff where you dine in the courtyard to a beautiful authentic Italian lunch with proseco and wine included. Then off to Pompeii bring a hat, umbrella, water and comfortable shoes, this is hot and a lot of walking, but well worth it! There is also a quick stop at a cameo making shop that is charming and interesting.