Internet only working on mobile hotspot (Ipad 2)

Help,

My ipad 2 won't connect to internet, if I connect to a wifi network it says connected but when I go on the internet it won't load. Other internet services don't work too like the appstore and connecting to the server, so I can't reset my Ipad. It only works if I use another phone as a mobile hotspot and then connect to it via the ipad.

How can I fix this?