If you do not have a tested 1-rep max, the Epley formula can estimate it from any weight and rep count.
Ascending: start easy and ramp up to a peak set. Descending (reverse): peak set first, then drop weight. Full: both, building to a peak then backing off.
Strength uses 2-6 reps at 80-95% 1RM. Hypertrophy targets 4-12 reps at 55-87%. Endurance uses 5-15 reps at 45-72%.