Buying a laptop for university - little overwhelmed

I have no idea on where to begin.
There are so many different laptops out there.
I've always had a desktop computer, so I have no idea about laptop cpu's and gpu's and what to look for in the way of features.

I need a laptop for university, just for word processing and browsing the internet, steaming lectures etc
It needs to be light weight and and the battery life needs to be pretty good.


Any help would be much appreciated.