I am an Indian and I will be starting as a Chemical Engineering Ph.D. student in the US this fall semester and I am looking for some tips regarding how I should start networking before I start my graduate studies.
Professional networking is best done in person, therefore if you want to begin networking before you start your graduate studies your options will be limited. Check various social media platforms (Facebook, Twitter, Reddit, etc.) to see if any of the researchers/students at the school have social/networking groups set up. If they do, try joining/following those groups, introduce yourself as a new student and take it from there.
Additionally, check the university website to find the list of professors in the department. Usually these lists include their email address and a link to their research websites, or a list of their research interests and publications. Identify a couple researchers whose work interests you and skim a few of their most recent papers. Then, contact them, let them know you're an incoming student and you've read their work (mention a specific paper of theirs you liked) and ask if you could meet them to discuss their work when you arrive in September. That way, you can introduce yourself to several professors and make it easier to establish contact with them when you arrive.