New players to live poker should not focus too much on
tells of the others, more to focus on their own strategy and minimizing their own tells. Concentrate on what you're doing, as you look at the cards, when the flop comes, how you put your chips in for a
bluff or the nuts, speech play, body language for each scenario. Once you feel confidant enough, that you have minimized your own tells, then it's time to try and read others. This will all come with experience, also depends on moods.
However, personally. Eye contact is something I look for, if they are looking at you, without moving away, to me, it means they are relaxed and confidant. Looking away means they are not so confidant.
The "sigh" for me, it shows strength, disguised as being weak. It is very common among low limits.
Quick play/slow play. Takes their time before checking, tends to mean, they have something, medium strength hand. Betting quickly, for me, shows weakness, trying to intimidate. Calling bets quickly, for me, means they are on a draw.
Who is paying attention, or who is on their phone while in a hand, are they interested in the flop? Or are they messaging on their phone? Looking around the room etc, eating food, chatting up the hot chic etc.