To fix download pending error from Google Play Store:
Check downloads and updates
More often than not, the Google Play Store download pending error means that other apps are updating at the same time. You may encounter this problem if you download multiple apps simultaneously. To fix this:
Go to Google Play > Manage apps & device > Manage
You will see which applications are in the process of being updated or downloaded.
Press the X next to the app's name to cancel the download and proceed with downloading the app you want to download.
Check your connection
This may sound silly, but checking your connection should always be one of the first steps. If you are using Wi-Fi, open a website on your PC or test your Internet speed. If Internet speeds are good, but the download is slow, restart both your modem and device.
Also, make sure you’ve enabled data downloads:
In Google Play Store, click menu button (three lines) in upper left corner
Go to Settings
In App download preference, select Over any network
If downloading resumes as normal, your home or office network is to blame. Restart your modem and, if all else fails, call your Internet service provider.
Check your storage and SD card
A common cause for Google Play problems is a lack of storage on your phone or SD card. Usually, you will receive a notification when your mobile device's storage is low. However, to make sure storage is not causing the download to pend:
Go to Settings > Storage to check how much free storage you have.
Try to download the app again.
Restart your device
If you are not downloading other apps, your connection is fast, and you have enough storage, restart your device.
Download apps through your browser instead
You can try circumventing the download pending problem by downloading the app directly from your mobile or PC browser. Visit the Google Play website and log into your Google account. Type MaintainX into the search bar and follow the download instructions.
Clear Google Play app cache and data
Go to Settings > Apps
Click Google Play Store
Make sure Google Play is closed
Click Clear Cache
Click Clear Data