Install aonther louncher, I installed Nova Louncher.
Problem was, that JOY Louncher alwayes crashed - so I could't start anything. So I pressed home button long => Google OK opened, I typed play and choosed play store, installed nova louncher and choosed it when it asked me which louncher should be used.
I'm very angry about alcatel POP S4- never by a china handy again, big brother is watching and tehrefore performance is slow ! Can't get rid of facebook and insta too. I bought a motorola phone now