We bought season passports when Lagoon opened back up and we have been a handful of times so far in the past few weeks.

During the week the park is generally not that crowded. The popular rides will have a max 10-15 minute wait and the unpopular rides will be walk-on. We have been able to hit all the kids' (all teens) favorite rides in a couple hours. With that being said, my wife took the kids on Tuesday and she said it was the busiest she has ever seen it, even pre-corona. Some people were saying it was so busy because of a deal that was ending in June. I mention that because YMMV on the crowds.

For the < 24 month old it really depends on how many rides you anticipate they will want to go on. Most rides will be $4-5 each, but if you think they will want to ride more than 10 times it would be worth it to just get the ticket. At 23 months old my guess is that your kid will want to ride more than 10 times, even if it is just the lady bug bop over and over again.

I don't remember what the height restrictions are at lagoon-a-beach because it doesn't affect us, but the water park there is pretty underwhelming for older kids. The kiddie play area is pretty good, but there are really only a handful of slides for older kids (I think 9 total and 1 was out of order when we went). Our teens only lasted there a couple hours before losing interest. The lazy river is the worst I have ever been in. It is extremely shallow so you really need a tube. Trying to swim it is just painful.

My 2c