Charge your laptop twice a day?

I borrowed a laptop from school. I use it both for school (video conferencing, research, etc.) and privately (Netflix, YouTube, online shopping, etc.). So I have to charge it twice a day. When I only have 15% left, I recharge the laptop to 70%. Since the laptop belongs to the school and I don't want to cause any damage (because we don't have the money to pay for it), I wanted to ask whether that's good for the battery at all, changing it from so much to so much twice a day % charge? Or does that break him?

So mine is on the power grid 24/7 and if I take it off, it goes empty after 3-4 hours, I asked my father who said that this is normal

It's OK. It is correct that the battery is not completely empty or full. Charging twice a day is normal, laptops are now designed for this. It is better to make sure that there's a suitable shelf, so no blankets underneath so that the ventilation does not get dusty