Why should people who live in the coastal areas learn about currents, waves, and tides? Give examples of how waves and tides could affect everyday lives.

That sort of thing could be potential danger. Not only for the environment but also the civilians. if too strong, waves can cause things like floods.

Well, currents, waves, and tides could cause dangerous events. If theres a Tsunami, the people near that area need to know how they are caused and how to get away. They will need to find safe places so their family won't get hurt. Other things can happen too. Sometimes, currents can pull people into the water without being warned. This can cause drowning incidents. (This is outside of my answer, but to be honest, I think everyone should know the dangers of these things, no matter were they live. What could happen is sommeone who doesnt live near the coast would want to go to the beach and without knowing about currents, he/she could get into terrible danger).