Practice small conversations with mirrors, imitate patterns, body language, and interactions you see come from people. Failure is natural at least once but attempt to learn from it, understand that you will fail and will stumble on the march. Practicing with a close friend (or a remote person you do not mind) is a great benefit and boon.
It takes a long time to feel natural at socialization, there will be quips around it, but as you continue to get used to it you can always adapt to the best.
The routine normalizes everything, even if you are afraid, even if it was not productive at first. Ultimately, as this becomes a comfortable zone, your feelings of being socially insufficient, or "NEET" will disappear over time.
In the context of your work, in the meantime, you can try to develop skills that you can later incorporate into your resume so that you can look better off after graduation. You should not try to support yourself when going to college because of the exorbitant cost. Unless you have a large loan or student allowance, please stay with your mother or divide costs with a roommate while you are enrolled in university.
Good luck, OP.
not op, but i really needed that. thanks