Bus 1 (¥1) is the only local bus you're likely to need. It runs from out front of the train and bus stations, along Xinghai Nanjie near Xīngchéng Old City South Gate, terminating at Xīngchéng Beach on the 35-minute trip.
A taxi from the train station to the beach costs ¥15 to ¥20.
You can catch a ferry to Júhuā Island. Ferries depart the northern end of Xīngchéng Beach at 8.30am, 10am, 11.30am, 2pm, 3pm, and 4pm. Return trips are at 1pm, 2.30pm, 3.30pm and 5pm. Frequency drops outside of these summer hours.