How do I unlock forgot pattern

I forgot my pattern for my Samsung and I have been trying to get into the phone but it keeps going to all sorts of stuff right now I have a bunch of barcodes up there and if I if I push the volume button it's going to go to downloading do not turn off Target I don't understand what that means then I can hold all the buttons and it's supposed to go to the reboot screen but the reboot screen will not come up the wipe it clean the anything there's only two screens I can get to come up please help