Sim Not valid when activating my iPhone
Phones are a bit tricky. On one hand, the manufacturer (Apple) should make it clear how to use the device, but since you get a no-service error that part of the equation seems working well enough. 

If the device shows no service with several known good SIM, you might need to check with Apple or the carrier that originally locked the device to verify it's unlocked + test with an active SIM from that carrier. 

If you can use the phone on wifi, it's activated (in the technical sense - activation is a specific step needed before the phone software starts to operate) and now you can focus on establishing cellular service and troubleshooting that portion of iOS:


http://support.apple.com/kb/TS3780