How do initial HH meetings go down and when should I start replying?

Hello - I'm currently a senior graduating this spring and will be starting my full-time career in investment banking this summer. Starting earlier this year, I've been getting emails and LinkedIn messages from buy-side recruiters asking to schedule an introduction call, join an upcoming virtual info session, etc. I'm interested in hearing about what will be discussed in the initial calls and what to do before I reply to these HHs. As a senior, I feel like it shouldn't be too make-or-break but would like to hear people's input.