You don’t need to be “good on camera”
Most people don’t need to “get better on camera.” They need a calmer set and a script that sounds like something they’d actually say, because the pressure to “perform professionalism” is what makes them feel awkward and unnatural. Fix the basics (pace, human language, permission to be imperfect, and getting one honest take first) and presence takes care of itself: slow the room down, make the words real, roll.