why cant i download anything on my samsung a3 either on google or app store, please help

[AC Question]

I tried erasing everything on my handset but still am unable to download

 

[ShilpaRiktam]

Open your Play Store and tap at the top left and choose My apps then Update all.
Make sure that you have the latest software update by going to Settings > More > About device > Software update > Update
If it doesn’t work, then back up all your important files and factory reset the phone via Menu > Settings > Accounts > Backup options > Backup and reset > Factory data reset.