As a rule of thumb the poker card order goes from Ace (A) to Deuce (2), with Ace being the highest card and Deuce being the lowest.

In Texas Hold 'em, having 2 and 7 off suits is rated the worst hand. This is because they're the two lowest cards you can have, and they can't create a straight (there are five cards between 2 and 7). Even if they're suited, they'll give you a low flush, and if they both create pairs, it'll be a poor hand.