I live with my parents, and my father sometimes invites people to gather for Qur'an recitation mixed with practices from the Tijaniyyah order, including bid'ah like Salat al-Fatih. They expect me to join. As a student living at home, how can I avoid participating respectfully?

Do not take part in the innovated gathering, and Allah says, the meaning of which is: do not cooperate in sin and transgression (al Maidah 2). At the same time, be gentle and dutiful to your father. Excuse yourself with kind words, keep honoring and serving him, and make dua for him, for parents are obeyed in good, not in disobedience to Allah.