The Jacksonville Beach Pier is open again after damage from hurricane Mathew in 2016. I don't think they are allowing fishing just yet but soon I hope.
Go to your city and county Parks and Recreation Web site and enter ADA accessable fishing sites and you should get a list. Choose a site contact an old school tackle shop and tell them where you want to fish. They can give you tide, tackle, to get you started. Personally I like moving water 4 to 12 feet deep.