No. You would have to receive a summons to appear. Then once you are there. A selection process starts. Lawyers and district attorneys interview prospective jurors to determine if they would serve well in that particular trial. If they are not satisfied with the answers, they will not qualify to serve on the actual jury. However, if you do receive a summons, the court will pay you for up to 4 hours.
I don't think you can volunteer. Your employer has to let you off for jury duty and can't fire you for that reason The court pays you for your time and gas mileage. Not what you normally earn but a flat rate that every person serving gets.
Jury duty is not volunteered for and the jurors usually have been picked by random selection to ensure there are no ulterior motives and to help in serving justice. You will usually receive sermons from courts and then the jury for a particular case is picked. Employees do not have to pay for jury duty but they are expected to give permission by court as ordered by law.