I think the port currently opens at 10:30am. But boarding does not begin until 11:30am and will be in boarding groups that are numbered. The people with the early port arrival times will be in the first groups allowed to board. So, the most important thing is to get an early port arrival time. Those are given out when you do your online check-in. I guess this is your first cruise, so you can check-in 75 days before your cruise beginning at midnight EST. People who are returning cruisers can do online check-in earlier, so you might not be able to get a very early time. You are free to arrive later than your assigned time and they will also most likely let you into the terminal earlier than your time. But your boarding group is determined by the port arrival time. After the first rush has died down, they will start to announce "open boarding" which means that everyone can board regardless of their boarding group.
So, if you are there at 10:30am and have that as a port arrival time, you will still have to wait until they start boarding and then for your number to be called. And even if you manage to get onto the ship with one of the first groups, some things might even not be open yet. Personally, we like to arrive around 11:45am to 12pm. By the time we got through security and were checked in it was always open boarding. By that time the terminal was never too crowded. We went to lunch immediately after boarding and by the time we were done with lunch it was 1:30pm and we could go to our stateroom and drop our carry on luggage there and then head out to tour the ship.
Personally, I found the first time boarding the ship a bit stressful and confusing and would recommend to just take it all easy and not try to put too many activities into those first hours. Enjoy lunch, tour the ship. While the pools might be emptier in the first few hours, there are other occassins when the pools are not too crowded. I often skip an evening show to use that time to be at the pools as they are really empty then!