Chosen Solution
So I recently bought a iPhone 7 and I transferred my sims card to the iPhone 7 that was in my iPhone 6and it says no service but my sims card is activated
You should really just take it back to where u bought it, few reasons for no service Phone is blocked/blacklistedFault with phone I.e baseband, etc.Incorrect networkWhatever the reason though if uve just bought it just take it back and get it replaced