The first day I would build
Give the city one clear route before adding extras.
- Start with Rock of Gibraltar and Cable Car while energy is high.
- Use Main Street as the natural reset instead of crossing town too early.
the easier plan is Rock first, town and shopping afterward, Europa Point if time allows. 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 Europa Point just because it looked close on a map.