The first day I would build
Give the city one clear route before adding extras.
- Start with Xingcheng Ancient City and Longwan Beach while energy is high.
- Use Jiumenkou Great Wall as the natural reset instead of crossing town too early.
the easier plan is Xingcheng Ancient City first, beach time afterward, Jiumenkou as a separate half-day. That keeps the day readable instead of turning every good name into a separate detour.
I would rather leave one place for tomorrow than drag a tired route through Bohai coast just because it looked close on a map.