Please capitalize where necessary: the pollution of the oceans, the rivers and lakes by (plastics-)waste, but also by oil and chemicals, is one of the biggest challenges for the world society.
A: The pollution of the oceans, the rivers and Lakes by (Plastics-)Waste, but also by oil and chemicals, is one of the biggest challenges for the world society.

Please capitalize where necessary: early identification of families and children at risk must be a priority.
A: Early identification of families and children at risk must be a priority.

Please capitalize where necessary: before leaving i advise you to look in which period you want to go. i was there in august, it was very very warm. i find that not very many museums, but to watch, it is actually too hot in august.
A: Before leaving I advise you to look in which period you want to go. I was there in August, it was very very warm. I find that not very many museums, but to watch, it is actually too hot in August.

Please capitalize where necessary: such as the crystal dial covering, the dials, and the strap.
A:
Such as the crystal dial covering, the dials, and the strap.