I’m very new to the gym stuff so sorry in advance for possibly dumb questions, but here it goes! From what I’ve read if my goal is to bulk up and gain size then I should aim for heavier weights and less reps. So, something like ~4 sets of 8 reps with heavier weights would be acceptable for bulking?

However, after each set I rest for 1:30min but I can’t do as much reps in the following sets, is it normal? Or that means I should use lighter weights?

Another question I have is if is it normal that I can lift different weights amounts in different biceps exercises? I keep changing the load of my dumbbells when switching exercises. But I’m also not sure if that’s due to me being more tired after each exercise.

Last question, does the order of the exercises matter? For example, I’ve been doing this: bicep curl, hammer curl, incline curl, barbell bicep curl and I have to use gradually lighter weights throughout the workout.