the last one should be the one you feel like you can't... and then take the next day off on that exercise

i had no idea about this day of[f thing, until i tried to train hard to join the army when i was 28 (2004) and i hit a wall and then i finally looked it up online and sure enough... the army training guide said "take days off between training days"

you can train every day, you just can't train the same muscle group every day

also, just to repeat, and repeat... your food is really important, and beef is pretty much the absolute best for muscle gain... milk is good for energy as well but more for cardio because otherwise it is too much sugar