Accounts and Wallets are used interchangeably in BitShares; there are multiple permissions/private-public keys (Owner, Active, Memo) with each account.
Do you have BTS in your account that is open when you click the "Create Account"? Also remember to back up the *.bin file/password and since password managers are recommended it may be a good idea to save your private keys as well.
Also note the different between basic account name structure word-word versus more expensive premium naming: word.
RE: DEX Market Maker Tutorial: bits and btsbots