Why it wont turn on?

Ok so i messed a little in developer options and i choosed an option i dont remember what it was but it said something like your phone might not run well and then it rebooted,after a while it says "Android is upgrading","Optimizing app 2of122"and then black screen nothing happens i have LG JOY H220 so if u could help me with this is very frustrating thanks in avance

Sorry, that's not much to go on. If you don't know what you've done, we have no chance. You may well have to reset it.