1. Jeff was a pro strength coach a long while ago. He is more about injury prevention and bodybuilding (with wwe wrestlers) nowadays. Less about explosiveness and power like a lot of sports require. And even with his specialities, he is too black and white with his approach and unnecessarily vilifies certain movements. So talk his fearmongering with a pinch of salt. A movement is onty dangerous if you are unprepared for it. Jeff's own injury history clouds his judgement at times.
2. Just focus on fundamental movements for now as you are a beginner; you can adapt to any stimuli, do whatever you can with good form. Bench Press, Military Press, Deadlift and Squat if with weights. Pushups, Pullups, Handstand Pushups, Bodyweight Squat progressions (towards one-legged squats), and Lying Superman Back Extensions.
Good points of reference:
Weights: Alan Thrall, Athlean X
Bodyweight: Fitness FAQs (also a physio), Bodyweight Warrior
Just work your entire body and watch your form.