I had an accident today in my car.  I think i might need a lawyer.
I think you do too.  At least some kind of person who practices law as a paralegal.
What will a lawyer do for me?
They solve specific individualized legal issues and provide law services.
Where did the law profession originate?
Well in practice, legal jurisdictions can exercise their right to determine who actually is a lawyer.  So as far back as they've been determining that!
Will my lawyer know what to do?  How much education does a lawyer get?
Well it's hard to make a generalization for all people and countries.  Different work has different costs and different lawyers have varying degrees of education.