Don't use a full powered energy attack, like the Kamehameha, in a real fight while you're still learning cause it COULD leave you drained and out of energy at the worst possible moment.
Give my muse unwanted advice!
“So that explains why the others don’t use it frequently, right?” Videl did want to learn new techniques like the Kamehameha wave eventually but like the anon said there’s no telling how that might turn out for a learner like herself. She could only just use regular ki blasts and her aim was atrocious. Videl needed to reserve all her energy while she was just getting the hang of it all.