I agree with you 100% Joan. If you want to play blackjack, make sure it's a blackjack table you sit down at before you put up your money.
I also found that if you play blackjack make sure there are between four and six players at the table for better odds against the dealer.
I like playing at a one deck blackjack table, it's much easier to guess what cards have been played to know whether or not you will take your next hit.