I'm a boy in teen age and don't know how to masturbate. I can get aroused and achieve erection

 Hey there masturbation for a guy is quite easy. The most traditional popular way is simply to grab a hold of your erect penis and slide your hand up and down .  Some people like to hold tighter  while others  more loose.  some people move their hand faster and some slower. it is all what feels the best to you. Also are you circumcised? 

 There are many techniques for masturbating some are more complex than others. A good informational website is Jackinworld index. 

so if you search that you may find it helpful .

I am uncircumsised and I'm wondering if you really need lubrication. What's the best to use at home?

It's all personal preference. Many uncircumcised guys find they do not need to use any lube because they can slide there for skin Up and down over the head of the penis. But sometimes The head can get kind of sticky and dry and it might be uncomfortable masturbating. Without lube. If you get yourself around enough without ejaculating you will eventually probably produce a small amount clear sticky slippery fluid from the tip of your penis. This is known as pre-ejaculate and is your body's natural Lube. Some guys can produce enough of this and make the inside of their foreskin slippery and masturbate very well with it.
Otherwise you can use conditioner if you are in the shower that works very well. Or some sort of unscented hand or face lotion. Oil such as baby oil and mineral oil can be used but generally are hard to clean Up

Thank you for your help. I greatly appreciate it.

You're welcome if you have any other questions just ask