I used scatter to create an account, is it true that account creation is not free? How do I check how much it costs? I can see also via "http://eosflare.io/account/" that I have some EOS stacked in this account, what are the implications? what about the un-stacked EOS?
EOS account creation is not free. The creation of an account costs ~3KB of RAM, the price of RAM changes with time so the actual cost of the account creation varies. The cost of RAM can be seen here: https://www.eosrp.io/