Where do you get jurors?

Answer 1

It depends on the jurisdiction. But, as a very general overview:

The jury pool is drawn, at random, from the geographic area where a court's jurisdiction lies. The names are generally obtained from DMV or voting records or the like.

Once the pool has been chosen, a subset of that group is selected, called the venire. From this venire, in a procedure known as voir dire, opposing counsel and the judge exclude veniremen/woman for various reasons ostensibly relating to their fitness and impartiality. Once a jury of appropriate size has been chosen that is acceptable to both sides and the judge, there is a jury.