This was only our second cruise, the first bring 18 months ago on QM2 out of Southampton. We are late 40's with a 13 year old son.
I had filled out all of the relevant documentation on the web site and printed our SetSail passes well in advance.
We made our own arrangements to get to Barcelona so can't comment on RCCL from that point of view. We arrived at the port with loads of time to spare (just a bit early actually) at about 11:30 but were able to book in, although our cabin was not ready until 13:00. This gave us a bit of time to have a quick look round the ship while it was still pretty quiet.