We were there last month and called shore beach services as soon as they opened on our first day. We requested the number of chairs and umbrellas and the number of days, and by the time we got to the beach about 90 minutes later they were set up with our names on them.
There were also several sets up and waiting with "available for rent" signs on them", if you would prefer to wait until you arrive.
For us, we were a group of 5 and wanted chairs set up all together, and the advantage of booking in advance by phone was not needing to have my credit card with me, as they took all the card info by phone. When my college age kids wanted boogie boards later in the week, we just asked them to bill to the already established account, no need for cash or credit card.