how do i use wi fi, can it be used for downloads?

Answer 1

You can create a wifi connection to your router to connect to your own internet. In this case instead of using a cable you are using a wireless conection so you can do whatever you can on our internet anyway. In this case ensure you have wpa activated (I'd suggest against wep as its less secure)

If you are connecting to a public or private hotspot then you may be able to download. This would depend on the permisions and firewall of the hotspot. They may not allow access to peer 2 peer applications but you could still download via normal websites.