chun li is a very heavy footsie base character, her most basic tactics is use her movement speed and pokes to bait moves and punish, as well as to keep your opponent in an area where his/her moves are least effective.
jumping forward is generally a no no with her, because in my opinion, her jump is the second worst in the game (dont ever use the wall jump, because thats the worst move in the game!) behind hakan, although her jump in attacks are great (double hp, cross-up lk, hk). ideally the only time you should jump is when you knocked down your opponent and go for a safe jump.
first of all you need to learn the mind games of walk back and forth, wait and block, once you start doing that well, its much easier to bait out mistakes. and remember blocking lets you charge for ex sbk, ultra and super, all very dangerous moves.
the second most important thing is anti-air, because you cant do the first part well without being able to anti air well. she has lots of anti-air options, but they are generally bad (trade a lot) and some are only viable in some positions. for examples:
far jump - s.hp
mid range jump - s.mk, d/f lk, air throw, n. jump hk
mid- close range jump - s.mk, d/f lk, s.mp, n. jump hk
close range jump - none, so block
everything - ex sbk
and s.hk if he is standing quite close but you know he wants to jump, you can use it check his jump. it also work as a far jump anti air for big characters with slow jumps like zangief and hakan.
you will be much better, once you learn how and when to use what and train yourself to react to it instantly. and remember d/f lk anti air lets you combo into ultra 2, so learn how to use it.
reactions to fireball/punish with ultra/super is also very important, once you let your opponent know you can punish unsafe fireball and moves with ultra, your match will be so much easier because you can now walk forward and attack more, since they are scared whenever you have the charge. in fact most moves and almost all medium or heavy normals can be punished by super, so learn it!
the last thing you need is basic combos, most can be learn in trial mode. her most basic one thats not in trial mode is c.lk,c.lk, ex lightning legs and c.lk, c.lk, s.lp, s.hp
but i will show you more when i get a chance to play you
i will show you some of these stuff in practice the next time we play.