Transatlantic cruise and boarding after sail date

I have an upcoming transatlantic cruise that leaves out of Barcelona. My question is this: if my flight goes sideways, is there a process to board after embarkation day if the next three stops are also in Spain?

This is my first time traveling to Europe and I’m trying to plan for all contingencies. I’m looking at a flight that lands the day before, but I’m more concerned about the layovers and what happens in the worst case scenario.

I’m also looking at all flight options, but it looks like direct isn’t going to be available to me. Due to work constraints, I can’t fly in too early either. Booked as a bucket list cruise and now I’m concerned about the flight possibly causing me to miss the first day. I’d like my options please.