app store not loading

If you are in the UK then it could be Apple's servers although no indication of an issue is shown on their System Status site.

The reason I say that is I'm having same problem on both iPhone and iPad, plus this is on the Downdetector UK site at the moment.

I suggest you sit tight and see what happens because it will probably get sorted over the evening and you will have access back tomorrow.

You will probably find the issue will be intermittent (ie. work one minute then down the next), you just have to give it a little time to get sorted, unfortunately these things happen and I've found it's best not to get worked up or worried by it.

Don't forget this is one of Apple's core services and revenue earners, so that should/will focus their attention to get this fixed fast (or they will be loosing money).