[ayrotakesws]

1. Going to failure on one set per exercise and going hard on the other but leaving 2 3 more reps in the tank is a good rep range. maximum 5 reps for strength with higher weight and 8-12 for hypertrophy(building muscle).
2.If you know what you re doing it wouldn't be bad for your back, go watch some youtube tutorials for the exercises, squats and deadlifts can fuck up your back if you don't have good form.
3. Protein intake 2g-2.2g/kg(if you are not obese and have like 30-50% body fat.
And for calorie intake it all depends on the person's calorie maintenance, you want to be in a slight calorie surplus to build muscle.

1. So for me to build muscle to actually be stronger, I'll be doing lighter reps with more reps ofc.
2. I most likely won't be going too heavy, so that won't be an issue I hope.
3. 2grams per kilo? I think that's for a fully grown adult past the age of 20, right? Cus I'm a new adult if ygm, so i'd expect it to be a little lower? My dad was a bodybuilder and he told me 0.8g/kg. My bodyfat is about 10-13% btw.
So i need as many calories as I can?

0.8/lbs, not kgs. 0.8/kg is very very low, it's easy to take in protein so don't worry about it.
As for calories, you can calculate your maintenance on some calorie site and then go a little above it to ensure you are in a surplus. I don't know those measurements to give you a number of calories you have to eat per day.

OHH, so it's per lbs, thought it was per kg. I'd rather not say my weight as it's rather low and embarassing, but i guess i'll go for 2 per KG. That should be perfect for me. Also as I saw you say earlier, should I work out all of my body every day? Cus I was doing gym 4 days a week, mon-thu.