A call to the priesthood always comes in the context of the Christian community.
Sometimes it is the community which first senses a vocation among its members and encourages that person to begin a process of discernment.
Sometimes it is the person who first feels a call and looks to the community and the wider Church to test it.
One of the places to begin your discernment is to talk with your own priest, who may decide to put you in touch with a spiritual director and/or your Vocations Director.
You may be at an earlier stage of discernment, in which case you might want to be in touch with the National Office for Vocation (NOV).