Please help. i need to kow how much to curl{and need help doing more}?

first of all you just start off with light weight until your arms are warmed up,then you move up to ur max weight,then you do as many curls as you can until you cant do no more,and same with benching,but makesure you allways have a spotter watching you,i am also 14 lol 6 ft tall and weight 160lbs and work out too,i can curl 40 pounds in each hand and can bench about 145 to 150. Make sure you eat some protein like steak or meat before you work out to get muscle.