What are Gar's emotions toward his departure?

Gar is excited to go to Philadelphia but also nervous about what it means for his future and disappointed by the reactions of those around him.
Philadelphia offers a host of options to Gar—it offers the chance of a better life. The life he had in Ireland offered nothing but dead ends. However, he isn't quite ready to put it or his family there behind him. He loves them despite the troubles he's experienced. However, it's clear that he's trying to make himself excited for his journey and to convince those around him that he's ready to go.
One problem is that he doesn't yet know what life in Philadelphia will be like. This gives him a sense of uneasiness as he dreams of a somewhat blank future. He believes that things have the potential to be better—but it's a scary unknown.
The other thing holding him back from only feeling happiness is that he'll have to leave the people he loves, like his father. S.B. doesn't seem outwardly upset about Gar leaving, which hurts him. However, it's clear that his father is going to miss him greatly once he leaves for Philadelphia.

Gar has mixed emotions about his departure as demonstrated by both Gar Public and Gar Private. In the opening scene, Gar is optimistic about his departure to Philadelphia the following day and fantasizes about the opportunities that await him there. His ambitions and desire for a better life can no longer be contained by the monotony and hopelessness of Ballybeg. To him, his father and the group of friends symbolize the type of life that he seeks to escape from.
However, Gar expresses his disappointment on several occasions due to the fact nobody shows concern about his departure. He is particularly pained by his father’s lack of concern. In fact, during a conversation with his father, he pleads in his thoughts for his father to say one unpredictable thing that would cause him to stay in Ballybeg. Gar also expresses to Madge his reservations about leaving. It is therefore clear that, even though Gar looks forward to leaving for Philadelphia, he also has concerns about whether or not life would turn out for the best.