Lydia's dream
Lydia, who cannot wait to escape from Forestville, misses it when she finally leaves for New York. This is an example of situational irony. While she gets what she wants, her emotions and feelings towards Forestville change once she experiences life outside, reminding readers that our perceptions and desires can often change with experience.
Dill's music
Dill, who comes from a strict, conservative background where music outside of hymns isn't much appreciated, finds his escape and potential future through music. This is a case of situational irony. What his background suppresses becomes his means of liberation, highlighting the transformative power of art.
Travis
Travis escapes from his harsh reality by diving into his favorite fantasy novel. However, his real-life tragically ends, much like the life of his favorite character. This ironic twist deepens the tragedy of his death and underscores the grim reality that he was trying to escape from.
Dill's faith
Dill is the son of a preacher but struggles with faith throughout the novel, an instance of dramatic irony. His skepticism and questions about faith stem from the trauma and hardship he's experienced, providing a critique of blind faith and the need for personal spiritual understanding.