I would first come up with a nice topic you are interested in. After that, I would search for a community that has an interest in that topic. For example, ISPIM is a large international community where you can find many kinds of researchers and topics. LinkedIn is a well-established platform:
Please let me add that Elsevier is a huge, dedicated well-functioning community where you can find help when you need it. Please subscribe to the following services:
1) Empower researcher career-building and network development https://www.elsevier.com/academic-and-government/researcher-career-network-development'