By the time next year’s season rolls around, visitors to Tybee Island’s North Beach will get a totally different experience. In a pair of votes Thursday, the Tybee Island City Council got started on two long-awaited projects — the removal of several derelict structures and the construction of a new beach entry plaza that includes restrooms and showers. Tybee Island Councilman Paul Wolff, a member of the city’s infrastructure committee, said Thursday the goal is to begin work on both projects this fall and have them finished by summer 2016. According to the beach management plan adopted by the island’s Beach Task Force, a now-submerged sea wall and more than 130 groins were installed on North Beach several decades ago to contain sand and protect the island. But these days, the old structures do more harm than good.