Huawe P8 Trouble downloading applications from google play store

First thing I would do is to get sure you don't have any problems with your Google Play app. Try removing it from your device and installing latest version from this website. That's what I did and it fixed a couple of problems I had with mine.

After that, check if you don't have any config on your device that allows your phone to download an app ONLY when you are connected to Wi-Fi.

you can ask for help ,

1.Huawei Forum:   http://cn.club.vmall.com/forumall-1.html
2.Huawei terminal technology support platform： http://consumer.huawei.com/cn/support/index.htm      
3.Customer service:    QQ：800008725  or  call the  hotline：4008308300