Didn't notice where you lived. Things might be different over there. I allowed students in my night classes as young as 12, as long as they met my requirements.
I still think it would be best to start with a tutor, but at least take a few tips.
Clothing.- Arc welding poses more danger than just the little spatters of hot metal, you can get a severe burn from the UV and infra-red rays. Don't wear fuzzy stuff. An old long sleeve cotton shirt. Like the US GI's wear, starch the heck out of it. Keep it with your welding gear. That way you won't have little holes in every shirt you own. Wear it buttoned up to the neck and tucked inside your gloves and outside your pants. Wear your pants without cuffs and long enough reach the tops of your shoes. Wear leather shoes, boots are even better. I've seen tennis shoes melt right to a person's foot. Not a pretty sight!!
EYE protection - UV and Infra-red rays. even just a few seconds can cause headaches and eye irritation. We all flash ourselves sometimes. Most of the time it doesn't bother you, but if your eyes start to burn, don't rub them, stop welding and treat them. They sell drops for this, but the juice from a white potatoes will do the same thing. If one treatment doesn't help right away, then go to a doctor.
Never weld on galvanized iron, the zinc fumes will make you ill.
Eveyone here has given you good advice.
Keep the duty cycle of your welder in mind, if have one of those buzz box welders, wouldn't want you to burn it up. If you don't understand that, I explain it.
Suggest you practice on 1/4" to 3/8" flat butt joints to start with, then move on to "T" joints.
If you are working in the garage, make sure there is nothing that will burn within 20 foot. Those little hot cherrys will lay on paper or cloth and come to life hours later.
Good luck
