Hi Philippek,
Let me try to answer your questions one by one:
1st: If you are not able to find your CS6 in your Adobe account, it means you might have not registered it. In case you want to find your serial number, check this. Find your serial number quickly
2nd: CS6 is last & most latest perpetual product offered by Adobe. Above that, you can chose our Creative Cloud products. To know more about Creative Cloud, check this. Software and services for creative professionals | Adobe Creative Cloud
You can also check the available plans. Creative Cloud pricing and membership plans | Adobe Creative Cloud
Hope that answers your query.
Regards
~ Arpit