Ebittner:
I was lucky enough to find a good club in Vancouver when I was a kid. A good coach will work with you from stance to balance to footwork, speed bag and will show an interest in teaching you. I'd suggest checking around your local area and find out who the good coaches are. Some coaches will 'cherry pick' but the good ones will work with anyone who wants to learn, even the timid ones..and especially the timid ones. 85% of kids start boxing for one of two reasons: They LIKE to fight, or they are tired of being shoved around by some bully at school or wherever
Some coaches just make fighters, others make boxers out of sluggers, make pit bulls out of poodles, and sometimes tame an animal (A hard hitting sparring partner can do this real quick)
A workout will consist of doing everything to the tune of a three minute round with a one minute rest in between (This is pre-stone age, but methods haven't changed a lot)
You warm up for 2 rounds, shadow box for maybe 2 more then hit the speed bag and skip rope a round each. When you are warm, you might hit the heavy bag, then catch your wind and spar 3 rounds.. maybe one more later on
A good coach will work with you on the heavy bag and teach you technique.
To build stamina, we would go 2-3 rounds in the ring with the coach who held the medicine ball and he made you hit it.. and you could get so tired you'd want to puke. Speed bag comes after that, then more heavy bag work. Cool down on the speed bag and then... do pushups until you cannot do one more no matter how hard you try. After that, situps are good, just do 20-30 on the incline board. Train 3 days a week and go real hard, rest on your off-days. A workout will go for about an hour and ten mins. Meaning 17-18 rounds.
That's about how a workout goes. Fees were cheap back then. These guys coach for the love of the sport, and once you have trained for even 4 months you have enough experience that you are kind of in 'the brotherhood' I cannot explain what that means, but you will know after your initial 3-4 month break in period. After 4 months you will feel better than you ever felt in your life.
Lastly decide that you are going to have the meanest, fastest, hardest left jab in your weight division and train it real hard. You will win more fights too, and a good jab will get you out of trouble when you are tired or getting thumped. Oh yeah, don't drop your right hand (the most common mistake of any amateur, and many pros too)
Oh by the way, some of the most decent and good hearted people you will ever meet are in the fight game. (dunno about the pros though)
Good luck