I have started your following your level 1 and level 2 workout,
is it normal that i have sore at my back? as I have done pull up hold. it was hard for me at first and continue for 5 set for 4 reps.
Is it normal to have muscle sore
Yes, it is normal. After your body get used to the exercises, you will not be sore anymore.
It shouldn't be in your lower back, stretch it out both after your workout and on your rest days, take those days to do nothing but rest and recover if necessary