Kickstart my career with startup team...i need help

I want to start my career with a startup team. Currently, I am pursuing my final year of BE in Computer Science. I aim to join a professional startup team that aligns with my technical skills. I am not interested in a conventional professional job; instead, I am willing to work hard and contribute as a core member of a professional startup. In this environment, I believe I can get recognized for my work and live the life I aspire to. However, I am unsure how to approach this plan or achieve my goal, as I lack mentorship. Currently, college placements are ongoing, and most students are joining random companies without clarity about their career paths. Based on my goal, please provide suggestions.