If you have a MHL cable, you can try to hook it up to a TV to see if it will display on there. If so, try to see if your touch is responding. If touch works, your LCD is burnt out and you'll need a new one. If not, the whole LCD/Digitizer assembly is shot and you'll need a new one of those. You can look on EBay or Amazon to see how much the part will cost. If it seems affordable, look on Youtube before ordering to see how difficult the process is. If it looks to be beyond the scope of your abilities, have it repaired or buy a new phone. Good luck!