iPad air won't connect to internet

new air, 128 gb. Unusable. Won't connect to wif with consistencyi. Won't load on new mail unless I power off first. Even then, it takes forever despite ultra high speed connection. (old iPad works fine). Can't navigate to links from sites or between pages, will say "server not responding. Can't even move within pages of a site.

what do I do? 900$ down the drain?

gail hill