Hula is Hawaii's own regional dance with very religious roots. I don't claim to be an expert by any means - but it's something that most elementary schools will teach the basics of at some point during a child's education here in Hawaii. (We can't have Lei Day without hula at school assemblies!)
There are 2 major types, Hula Kahiko and Hula 'Auana, which I feel refer more to the style of music the hula is danced to and costumes worn.
Hula Kahiko is the ""old style" of hula, often accompanied by a percussionist (most often an ipu - as demonstrated by Nemu in today's strip) and vocalist/chanter. The costumes are usually traditional in style. Haku leis or tightly woven leaves, ferns, and sometimes flowers are worn on the head while flower and leaf leis are draped around the neck/shoulders. Ornaments made of animal teeth or black kukui nuts are also worn around the wrists and ankles. The dancers will often call out verses (in Hawaiian, of course) in response to the chanter.
A familiar scene in Waikiki in the evenings
The more recognized modern style is called Hula 'Auana. There is often a band with guitars, ukulele, and other instruments. The songs are usually more "melodic" in style. Costumes range from simple mu'u mu'u (like Kana is wearing in panel 2) to elaborate stage costumes. The dances tend to be slower and more graceful in style - popular at public events and around Waikiki.
Other than those slight differences, the basics of hula are the same - all of the motions and gestures help to visually tell a story that the chanter/vocalist is singing about. Technically anyone can learn how to dance hula, but it takes years to master the art.
Unfortunately for Kana, I can't say that practicing with the hula hoop will equate hula mastery~ ^^