I parked at Canada Place last year for my 7-day cruise after driving up from Oregon. Entry is easy; just like any other parking structure. No assigned space, but there are areas for longer term parking. I was staying one night at Pan Pacific so very easy to access hotel.
The only issues I had were upon exiting the garage at the end of my cruise. I had a bar code which should have opened the exit gate. Unfortunately, it wasn't working. Had to wait for one of the few attendants to wander by and see that there was a problem. It took them a few minutes to get the gate to work. Also, be careful when you book your reservation that you specify your arrival time at Canada Place. The website defaults to a midnight arrival time on your arrival date so I got charged for an extra day. I tried to resolve the matter after the fact, but company was not responsive. Things may have changed since then.
I got Covid the last day of the cruise so I was happy that my car was waiting for me in Vancouver at the end of the cruise.