I've made it...And I reset the account too. I don't know what to do :S
1. Clear the Play Store cache
Settings > Apps > All Apps > Google Play Store and then finally tap on
Clear Cache.
2. Clear the Play Store data:
In order to clear the data,
Settings > Apps > All Apps > Google Play Store and then finally tap on
Clear Data.
3. Uninstall Play Store Updates:
In order to uninstall updates,
Settings > Apps > All Apps > Google Play Store and the finally tap on
Uninstall Updates.
4. Clear Data and Cache on Google Play Services
In order to do this,
Settings > Apps > All Apps > Google Play Services and just tap on
Clear Data and
Clear Cache.
5. Reset Your Google Account:
In order to reset your account,
Settings > Accounts > Google and then tap on the menu at the top and tap
Remove.
Next, go to
Settings > Accounts > Add New Account and simply add the same account again.
6. Factory Reset Your Device:
In order to factory wipe,
Settings > Backup & Reset and simply tap on
Reset Device.
If nothing works then there might be some problem in the Google Play Store servers. It happened to me once and turned out the problem was at the server end. Which got fixed itself in a week or so.
Also it can be a firmware problem too ,like if i was on Android 7.1 (CM14.1) play store stucked at downloading but back 0n stock rom it works good)
Hopefully, one of these workarounds will fix the issue of Google Play Store not downloading. Feel free to leave any comments below and we will get back as soon as we can.