i want to grow my bangs long but they stop growing at my eyebrows.someone said its because i wear a hat too much and it damages my hair.is this normal or some kind of male pattern baldness sighn for the future?

Well I am not sure about the whole "some kind of male pattern baldness sighn for the future?" but I do probably think the hat you wear alot is slowing down your hair growth.
I have been wearing extentions in my hair, since January. Off and on.
Now my hair is in such bad condition I just decided to leave them out all together, and just put up with it being short the time being.
This has been about a month now, and my hair has hardly grown at all, my hair was always fast at growing, but I seriously think because of the lack of air and sunlight my natural hair has been getting, I've just damaged the root system.

Why do extentions hurt hair? I thought you just stuck them onto yr hair

Yes you stick them onto your hair with GLUE!!!
Of course you can sew them in [if you know how to do it] or get them professionally done in a salon, but a quick and easy way to do it, is just with hair glue.
As you can imagine, trying to get glue out of your hair, no matter how much conditioner you put on the glue, to make it disolve, when you pull the hair piece out, you still rip out ALOT of hair with the glue.