tranny problems

when im driving and startting off when its about to swith in to 2nd (automatic tranny) it kicks back hard like its jumps and when im sitting at the light the rpms just drop to 0 and it dies. does anyone know why that is

Shifting hard could be a lack of tranny fluid or the tranny going out completely... The dying at an idle could be many things. Loss of spark, loss of fuel, bad sensors, idle adjustment screw, etc...