The 12# of soda was what the bleachcalc spit out for a pool of your size to raise TA from 20 to 80 ppm.

Try not to overshoot (80-125) with this, because it is not so easy to lower TA once you get it too high. Similar with the CYA... only way to lower CYA if you overshoot is to drain the pool, hence the good advice not to mess with it for at least a week.

Have you been swimming yet??

ETA: the rest looks good, and it IS easy, if you keep up with things every day! (I have had pools in the past!)