Introduction
Building relationships is a longer-term game than just talking to people who can help you get a job. Similar to note taking, it isn't as important what your system is for keeping track of the relationships that you build as it is that you have a system. Figure out a process for a "personal CRM" whether it's a Google Sheet, Airtable, or Roam Research. Keep track of who you meet, where they work, when you meet them, what you talk about, what you learned from them, and what kind of investing they do.
The worst time to build these kinds of relationships is when you're looking for a job. Focus on quality relationships first and then the job opportunities will follow.