OT: wifi computer help please.

[Cicli]

Lets start with I dont know squat about computers or networks. Now, I have cable internet and its suposed to be good. My wifi is a Apple airport that is about 8 years old. My internet at home is slower than if I just use my cell phone on the carrier network. It works but not good. Do these wireless things go bad? As in deteriorate? Would it help to plop down the cost of a nice cassette on a new wifi thingy?
Just trying to find a solution without getting too technical. Thanks for some help on this.