We went to the liberty park in summer from NJ side...

We went to the liberty park in summer from NJ side.
If you want to view the city from crown, book it in advance I would say atleast 5 months ahead., and it's worth watching.

For pedestal tickets, I'd say it takes atleast 3 months in advance to get tickets especially in summer.

The park is maintained well, and there is no time limit. The only time limit is the ferry timings that takes you to and fro from the NJ or NY side.
Parking is available.