I've spent my working life explaining Physics to teenagers.

I teach Cambridge Physics: O Level and A Level: to students preparing for their exams. Most of them arrive able to recite formulas and unable to say what any of them mean. That's the part I fix first.

My sessions are conversational. You get asked questions, you get things wrong out loud, and you get corrected before the habit sets. That is a much faster way to learn a quantitative subject than sitting quietly and copying.