rooting my lg l9 with 4share

To root many phones, the rooting program uses some vulnerability in the phone to get around the fact that in order to copy su to the phone (which, basically, is what you do to root the phone), you need root access - which you don't have, which is why you're rooting the phone. Evidently LG figured out what vulnerability that rooting program was using and patched it.

Kingo might root the phone. Try it. Root Android phone, flash custom ROM and manage your Android devices, Rooting Freeware Download - Kingo If it can't, it won't hurt anything, it just won't do anything.

Then you can search

adb root android

There are a lot of sites that show you how to root the phone manually. If your phone is capable of that, it takes about 2 minutes after you've installed adb.