This program is meant to push you till failure.
It is normal to not be able to finish all sets and reps for all the exercises.
For example, if you have to do 10 pull-ups and you only get 5 full form. For the reps left over, do the progression that works for you explained in our pull-up tutorial.
Also, if a week is too difficult where you cannot even finish the reps with the progressions. Go back and master the fundamentals explained in the tutorials before you move on. Then repeat that week until you get at least 50% reps finished, and then move on to the next one. The key is to keep pushing yourself.
Keep moving forward Bar Brothers salute!