I can not use my play store app
Make sure you have internet connection. Such screen appears when there is no internet connectivity. As I can see from the screenshot, that you are connected to a WiFi, make sure internet is available from that source.

I have recreated the similar situation. Connected my device to a WiFi which has no internet connectivity; Opened Play Store and this is what I got.


Screenshot (click for larger variant)

So, just connect to a stable source of internet and you will be good to go :)