i downloaded about 10GB of apps yesterday. This morning apps would get stuck at waiting and not change to loading. This is what worked to fix the problem for me.
Quick solution to can’t sign in to apple app store or iTunes: get a new IP address.
I soft reset and hard reset, tried to download the apps again with no luck. Again they would get stuck at waiting, no result.
I signed out of iTunes because a post on the official Apple support forums said to do so, but then it would not let me sign back in. Other people had random suggestions on there, the worst case being a full factory reset of the iPad. It all seemed like random solutions, no one really KNEW what to do.
i called Apple tech support using the telephone number on their contact us page, they tried, but were ultimately unable to fix the problem. Apples Email support said call telephone tech support.
I fiddled and tried lots of fixes to get the downloads started. The key check was trying to create a new account on the device after I signed out. This did not work. So now I knew it was a problem with the Apple servers. Websites and safari worked fine during this time, it was just the app store that didn’t work and downloads were stuck at waiting.
I tried a separate IP address through my ISP and this fixed the problem and I could sign in and download again! So that was the solution.
Solution: because of the large repeated and large downloads yesterday my IP address was probably blocked by Apple iTunes servers. That is why I could not sign in to the system. It is possible my IP address is now on their spam list.
Temporary solution: change to a new IP address through your ISP. i hope the Apple server unblocks the IP address after 24 hours and everything should be back to normal tomorrow, but it could take a few days, depending on when Apple refresh their server block lists.