Sounds like a kid who could really use the Big Brother program or similar mentoring thing.
I blame YOU for lodging this chunk of tomato up my sinuses >:[
No, seriously, I can’t get it to come back down now and it really hurts.
Pretend I wrote this, except I’m 36.
He’s been on the waiting list for Big Brothers for about five years now. Men aren’t exactly jumping out of the woodwork around here to be active mentors.
That would be the Learn About Middle Age Chia Pet ™
If you’re looking to give him a male figure in his life, I guess it couldn’t hurt to advise the Boy Scouts. I was never one (Ok, for 2 days I was) but I hear good things from guys who were Boy Scouts.
And paintball and go carts… sounds like an excellent manly way to spend time. Shooting people with little stinging balls of paint and driving as fast as you can get it to go… totally manly. One suggestion, if you’re doing them both the same day… do the paintball last unless you have a place for everyone to shower and a change of clothes for everyone… paintball is messy… bring a drop cloth for your car. 
I say get your son and his friends (not too many friends) tickets to a big rock or pop concert. Maybe enlist an older brother or sister of one of his friends to chaperone. It’ll be incredible.
There are lots of manly things a mom can teach.
How to start a charcoal fire and grill a steak.
How to write checks and balance a checkbook.
How to take responsibility for his deeds.
How to settle disputes without punching anybody. This is more manly than some people think.
How to cook and clean, so he won’t have to marry the first girl who doesn’t chase him off.
How to understand electricity.
How to use condoms until he’s ready to support a baby for 20 years.
How to change a tire, and change oil.
You go, girl. We’re pullin’ for you.
Is there a place you can play paintball while driving go-karts? Because that would be totally friggin sweet!
Superbowl Sunday!!
Rent “Hedwig and the Angry Inch” then, after his buddies all run home and he comes to you with glassy eyes, give him “The Straight Dope”, so to speak.
I think this deserves repeating. And to add one more, which is probably best taught by a woman anyway.
How to treat a woman.
Oooh - after the paintball, take him to a hockey game. Quite manly, that.