on the first day or embarkation day, there is open house, you can go with your child, see how things are, talk things through with her, ask CM questions etc. Also this is a good time to get registered, they'll put a magicband on her wrist. There will be other open house scheduled here and there, and when they do they'll shut down either the lab or club, but not both
Next day, it opens at 9am, and you go with your child to the entrance. She'll tap her magicband and will be registered that way. The glass door will open and that's where you'll say you good byes.
There are events scheduled throughout the day, but due to covid things have slow down a bit. They are starting back up but expect one every couple hours. It'll be on the navigators.
Our mistake with oceanier's club/lab was dropping off our DS4 like it was daycare. He became really anxious and broke down after an hour asking for us. So would have been better had we done baby steps, starting with 30 min, so he knows we would be back for him and didn't abandon him. But if something is wrong, CM will message you through the navigator app.
I would ask the CM if they plan on feeding or giving drink, our sailing on Wonder was no food or drinks, only the water fountains and couldn't bring any food inside either. Was strange but it limited how long we're comfortable how long our DS4 and DD7 being there at a time.
It's montisory like, where there are pods to watch movies or play games, or arts and crafts, or participate in events such a Sarge's ultimate challenge or Princess story time or Frozen play. So your kid could very well end up watching movie on the wall the whole time and you wouldn't know it until you go pick them up. CM also might not know their day as it's a big place with lots of kid going in and out and CM goes on/off duty as well