The course will also include a theory test, CPR and scenario training (simulated rescues).
Dell said the skills could be handy in many situations. One of her friends used his life-saving skills to help a person injured in a car crash.
"I'm excited to be able to know what to do in situations like that."
McDell will join stars including Carly Flynn, Mike McRoberts, Frankie Stevens and Guy Sebastian at Auckland Domain next Saturday for Christmas in the Park.
"I'll be there with Stephen Kent, who's an Olympian, crazy-good lifeguard," she said. "We're trying to get people to donate and talk about the important work and hours that go into lifesaving."
McDell's first single You'll Never Take That Away, released in February, was a No 1 hit. Her website describes her as a "shark-obsessed, dolphin-possessed water baby" who never strayed far from the beach, or her guitar.
Surf Life Saving's national appeal begins this week. To donate, go to surflifesaving.org.nz