Get used to the system first. This would go for any character. Skip over what you don’t need. Here’s a few things I’d suggest you get used to:
-Special moves. It’ll take a bit to get used to the motions for rekkas, for ultras, and for DPs. Both sides.
-Special cancels. Yang mainly special cancels from his s.lk, cr.lk, and cr.mk. In USF4, he’ll also cancel from f.s.mp.
-Chain cancels. Yang’s main chain cancels are his target combos. Chain cancels are something you can mash out, and not have to time. s.mp, s.hp, b+hp is Yang’s main used one in footsies and a Seiei-Enbu starter. s.lk, s.mk, s.hk is scarcely used, but it has some interesting follow-ups (i.e, ex DP in corner).
-Links. Yang’s main links are cr.lk, cr.lk, cr.lk xx rekkas; cr.lp, s.lp, cr.mk xx rekkas; and cl.mp, cr.mk xx rekkas (in order of difficulty, roughly). Muscle memory for this, but links are things you have to time (rather than just mash). For the cr.lk set, get used to pressing cr.lk+cr.lp for this. Muscle memory, again. It protects against throws.
-Plinking. the cl.mp, cr.mk link is a 1f link (1/60th of a second). Hard to hit. Plinking is a way to abuse SF4’s combo system. There’s a lot of youtube tutorials for it, but it basically makes the system give you an extra frame of leniency.
-Crouch teching. Easy to understand. Hitting throw prevents you from being throw. Hitting down+throw makes you stick out a cr.lk, but also prevents you from being throw.
-FADC. When you hit certain moves, you can expend 2 bars to cancel into a focus attack and dash cancel. You want to learn this for DP (particularly LK), mp palm, and for hp rekka, hp rekka FADC.
-Option selects. I put an easy set of option selects in the Questions thread. Check it out.
Make sure you get some basic knowledge of the system (when does a reversal happen? What are the properties of normals/specials?), and then look towards things like optimizing combos, footsies, and similar.