-How can i check my pages in zope?
not sure what you mean by that
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is there any easiest way of theming the website?
Unfortunately, there are no (other) themes avalable for Plone 5 (as far as I know), so you will have to do it with diazo:
http://docs.plone.org/adapt-and-extend/theming/
and maybe take a look at this: Easy Plone 5 theme customizing? -
how can i add more apps in my plone,
http://docs.plone.org/manage/installing/installing_addons.html
Not all add ons are ready for Plone 5, you can find some of them here: