What if you have never connected your iphone to itunes ? would i be able to long onto any itunes with my apple account and retrieve my seriel number or imei ?

i disabled fmip myself before i handed the phone to my friend sadly .. For the iphone was stolen from my friend and i never gave out my icloud password . its just strange that i cannot seem to see my device connected my account at https://appleid.apple.com/account/manage . it says Devices you sign in to with your Apple ID will appear here. and nothing is there . the service is currently off also so the person must be using wifi but i need to find a way to obtain the imei or serial number to lock the phone ... then when i log into icloud.com on the computer and i go to the "find friends" tab at the bottom i can see the name of my device and nothing else. so the account is still connected but fmip and the location is off . 😕

Even if i backed it up on itunes lets say i still cannot get my imei or seriel number . i know the thief and where they reside but at the moment i cannot retrieve it so meanwhile i was trying to lock it down ....