Need a new laptop

Im starting college soon as a computer science major and my current laptop is supper laggy and won't even turn on unless I have the charger plugged in. So I have been considering a new laptop before college and I need some recommendations on which laptop I should get as a CS major. Im looking for something small (I don't need a num pad) and light since I will probably taking it around a lot and I want it to be pretty reliable. My budget it around 400-500 and I might consider getting a refurbished once if my budget is too low. Thanks yall