I'd say bad idea on that, I have tried it and one of the guys I got weed from usually liked harder stuff, so he frequently tried to invite me to try them...
If you are introverted and cant say no or as society inept as OP seems, that is a very bad combo.

If you talk like that you will not get weed, you will get your ass kicked.
My suggestion is just find more friends, go to parties, go to college... There is literally zero chance you go to a college party and there is no weed. It is illegal where I live so even some younger assistants smoked....
But buying it for yourself is a bit different, and you just don't seem to have the social skills to manage that.
Additionally smoking with friends at a party is very different than smoking alone at home. You can get paranoid and with friends around they can calm you.
Finally wait until you are older, maybe 25 then your brain is more developed and you will fuck it up less.