What do I do if my playstore is not working on my phone?

Hi , if play store is not working try and clear the cache by going settings=apps=playstore app. then you will see a button called clear cache press it and check if it works. if i doesn't delete the playstore app and download one from the internet by writing playstore apk.i hope it helps you havd a nice day

First take contact backup then go setting and redtore factory reset.
then your play store works.

I would try uninstalling and re-installing the app via google play, first. Then try updating your password on for google on a desktop/laptop. Finally log in to the re-installed app on your phone. Hope this helps.

You mean App Store? Maybe because your password has been modified or the phone got reset on passwords and you need to log in again. Try that first. Otherwise you need check settings on App Store. Good luck.