need some printing help.

hey guys and gals, I’m new to 3d printing and still only learning, I’ve had a problem with prints not sticking to the bed, I’ve leveled it with a paper and its coming out of the tube as described in the ender 5 plus manual. I see there is an option to turn off or on the fan….what does turning off or on the fan really do?
I know its a method to cool “something.” but what exactly is it cooling? and does it affect my bed adhesion or print quality? My printer is in the basement where its always pretty cold, so if my basement is cold do I need to use the fan do you think?

I just recently ran out of the default filament that it came with and bought two rolls of overture brand filament and I’ve been having trouble ever since with it so I’m not sure if its my new filament thats giving me problems or what. I just tried printing with a brim setting and even that starts to peel from the glass bed really quickly. it feels like the filament is cooling way too fast, but I’m printing at a 215 nozzle temp and a 70 bed temp which I feel is already pretty high. What should I do?

The bed is clean as I wiped it with a Lysol handwipe and fiber cloth towel.

I’m using ultimaker cura as my slicer

any help would be appreciated 🙁