Skyscanner is a very useful tool to source the most cost effective way to reach your embarkation port, to search for which airlines fly there, & to compare fares.

Tripadvisor.com will detail accommodation & recommendations for a pre/post cruise stay, or why not consider Airbnb.co.uk  which often offers more unusual places to stay – how about a night on a boat berthed in Nice port before walking across to join your ship ?