No xm reception

3rd gen owner here with nav and solar roof. I just purchased a 3 year subscription to xm only to find out i cant get the signal to my car. Multiple trys have been attempted. I cant even turn the channel to get the free ads station. Ive looked up the diagnostic for infotainment and i believe everything checks out. Any thoughts? Do i need a new antenna? Can i snag a used one from the junk yard or are different trim levels different? Thanks in advance.