The right of free will is just as the term implies, that a person's will is under his complete control. That person may think as they wish, and attempt to act as they wish. The right to love is again self explanatory. Loving in many ways defines a person, and governs most of their relationships with others, God included, but love is not the most important thing which defines a human, for love without the free will to do so is effectively meaningless. Love is not just of the will though.
Love is the attraction of the soul to something, or more likely, some one.
Love is not really a conscious choice, but the free will of the person greatly defines their character and thus their soul, thus in an indirect manner controlling what that person loves. The right to serve is perhaps the most ambiguous of the three, though to a Christian this would perhaps seem more obvious. Love does require a measure of servitude. One who loves by nature wants the betterment of the object of his love and this usually entails working to benefit that object. It is in this way that love demands servitude, besides, the toils of others are far more bearable than our own.