May God continue to bless you in your desire to serve in the Vineyard of our Lord. I suggest you consult with your parish priest, you will need him-your spiritual father, and the metropolitan of the metropolis in which your parish resides, to endorse your application.
Because of the comprehensive responsibilities of the priest, any discipline will help you in your preparation. I think grammar is important, you will need to do a lot of reading, complicated reading like the scriptures and the writings of the Church Fathers, in your studies. Look over the books available through the Orthodox bookstores, especially those of all the seminaries, Holy Cross, St. Vladimir, St. Tikhon, Christ the Savior, and the Ukrainian seminary in South Bound Brook, NJ (I can't think of its name), which offer much information as a basis for your study of theology. Look over the websites of all the North American ecclesial jurisdictions, all of which have a vast array of information for study and spiritual growth. The links are available through the Assembly of Canonical Orthodox Bishops website. The Ecumenical Patriarchate of Constantinople and most (if not all) of the Holy Orthodox Churches offer websites with interesting information, likewise. I'm not advocating that you ignore your non-ecclesial interests, everyone needs variety in life. If you are on facebook, "friend" Metropolitan Savas of Pittsburgh, and you will see how diverse are his reading interests. Facebook offers plenty of Orthodox pages too; search them and see how many come up.
I recommend you plan on attending Hellenic College in Brookline, Mass, a fully accredited undergraduate college, which offers lots of Orthodox religious studies courses that are not available in any other American undergraduate institution. Depending on your knowledge of Greek, HC offers course work throughout the four years of undergraduate studies, so that your Greek language skills are up to what is needed for seminary studies. I think there is a discount on tuition, when you enter the pre-theology program, a declaration of your intent to become a priest. The Archbishop Iakovos Leadership 100 Foundation offers substantial tuition assistance to seminary students, and undergraduates who are enrolled in pre-theology, I think. Visit the campus when you can, perhaps your parish priest can arrange for someone to offer you a tour. If you attend a secular or Roman Catholic undergraduate school, you might need more than 3 years for seminary due to credit transfer issues.
Upon graduation from Hellenic College, Holy Cross School of Theology would be the natural next step, which is also accredited and offers a full time 3 year course of study. Depending on your financial situation, Leadership 100 offers tuition assistance and student loan repayment for priests assigned to parishes in the Holy Archdiocese.
The Clergy-Compensation schedule of the Greek Orthodox Archdiocese of America (GOAA) is listed above in reply No. 24. It is a generous package, requiring the parish to fully support a competitive health care plan for the priest and his family and the lease of an automobile, or travel compensation which amounts to the cost of a car lease, gas, and insurance. The priest is responsible to pay into the Clergy pension program, 2% or so, I think, of his salary; the parishes are required to support the pension system managed by the Holy Archdiocese, but they do not contribute to their priest's pension plan directly. It is a traditional guaranteed pension plan, something not being offered by most private sector employees these days. Some of the parishes are granting annual salary and housing allowance increases within the band based on the priests seniority, so that the priest will be remunerated at the top of the pay band when he achieves that level of seniority. This is typically far in excess of a cost of living increase. Today, the Metropolitan tells the Parish Council what will be the starting salary. Some good priests are remunerated higher than the band. But be aware that roughly 1/3rd of the 535 parishes in the GOAA are two small or do not have the resources to compensate their priests in accordance with the scale. Typically, there are priests who have experienced problems in their ministries, perhaps they do offer comprehensive ministries, who are assigned to these parishes, but also, often a young or another priest may be assigned to parishes like these in an effort to rejuvenate the parish. (I know a priest who was assigned to two declining parishes, in which he inspired a rejuvenation of those parishes, and is now serving one of the largest parishes in the Holy Archdiocese.) Also, note that if a priest is assigned to one of the few parishes that offer a residence (rectory) for their priests, the salary in the compensation schedule is reduced proportionately.
Attend all the Divine Services offered by your parish as much as you can; and activities offered by your metropolis. You may wish to attend Catechism and Bible Study if your parish or a neighboring parish offers these services. Attending services and activities in nearby Orthodox parishes will benefit you also; don't let our jurisdictional differences keep you away from enjoying the benefits of God-blessed pan-Orthodox fellowship. Such experience will serve you well as a priest too. Consider service as an Altar Boy in the Sanctuary also.
The GOAA ordains deacons and priests, who are determined qualified by the seminary upon graduation, once they are married, if marriage is their plan.
I sincerely wish you the very best in your path to serving our Holy Church as a priest.