Weight lifting advice

[HerculesShipwright]

DS is 17 and strong, and very solidly built. He's been lifting free weights using a barbell and dumbbells. Just at home.

I know nothing about weight lifting and am struggling to know what weight he should be lifting?

Is it safe for him to be using a barbell alone in his room. He lifts it when lying down and now wants to increase what he's lifting. Is this safe?

I would much prefer him to join a gym but his ASD means that's a real challenge.

Id really appreciate advice if anyone knows anything about weight lifting.

At his age he's better increasing the repetitions and not the weight to build his stamina. Ideally he should go to a gym where he can get advice when he needs it - but I can understand why that's not an option.

Thanks @PinkyGold I will suggest this to him. I'm going to push the gym option again. We have a small gym literally down the road from our house.