I cant seem to connect to my App Store.

Do you have access to another WiFi network where you can try? That has worked for several people.

Try a restart.

Restart your iPhone, iPad, or iPod touch         

Try a forced restart.

Reset Device.      

If necessary

Hard reset.        

Do a backup and try a factory reset. Then restore from your backup.

Restore to Factory setting.      

Backup - Restore your device from an iCloud or iTunes backup.      

It also might be a problem with your ISP. Are you receiving an Internet connection from your ISP? Is there an indicator on your router to see whether you are receiving/have an Internet connection. If your Wi-Fi network works, but you don’t have Internet access, your modem/router might not be receiving an Internet connection from your ISP.

I’ve had that same problem (several times) where my phone only connected to the Internet by turning off wi-if. The wireless network was working from my router, but the router wasn’t receiving an Internet connection from the ISP. I don’t know why it happens, but it definitely was an ISP issue.

The only solution for me was having my ISP (cable company) reset the connection to my modem/router. This is was problem with the ISP and I had to contact them to reset the connection.

I don’t know how your network is set up, or what kind of ISP connection you have. So the answer and solution may be different for you. I thought it was something you should check, though.

Your Wi Fi may need to be reset. Try restarting/resetting the router.

Troubleshooting Wi-Fi issues in IOS.    

From user, donv (The Ghost)

There are so many similar problems related to connecting to an Apple server that I have ceased trying to sort them out. I suggest you do this search (verification authentication failed apple server) or use my search link verification authentication failed apple server You will find quite a few reads that may be related to your problem. You also may want to use the support options below in dealing with your specific problem.

Get a call from Apple support to help solve your problem using this

link https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362

Apple ID Support https://support.apple.com/apple-id

Apple ID account security for country-specific and

region-specific help https://support.apple.com/en-us/HT204169

Get Support: We’re here to help https://getsupport.apple.com/. Go through

the options to find the best support option.