My 7mo old tried to stand and fell back into a book shel, has a med sz knot, stook 6 oz slept 30 min and pooped, but now has thrown up 2x. Concussion?

Could be... Everything you described could be a normal reaction to trauma, but with the persistance of vomiting an immediate evaluation is needed. Go to the er!
Unlikely/monitor. Babies who fall from their standing height are unlikely to have concussive injury unless they have: fallen into a jutting corner, been running, fallen onto exposed masonary. The kid who crys immediately & has a knot come up is less worrisome than on who is knocked out for any time period. An occasional spit up is common but continuous vomiting/bulging soft spot/personality chg all warrent er visit.