Michael,
There is no facility on the site to 'buy' a '1st year licence' as these are supplied with the PilotAware Classic, or (for Home Builders) as a code supplied when you buy the necessary 'RF Bridge' from PilotAware, which you then 'redeem' for your 1st year licence. The 'Renew your KEY' option is only for those who have already been running PilotAware for a year on a full license. You cannot renew from a 28 day demo license if you have never actually 'bought' a full system license yet - either as part of the 'Classic' kit, or with a 'Bridge'.
Regards
Peter