Job hunting and networking: what exactly am I supposed to do?

Asking here because neurotypical-oriented career advice has a LOT of implicit social rules that are left out. I was wondering if anyone here who has cracked the code on how to approach some very specific situations:

1. A person says "feel free to connect with me on LinkedIn", you do that and they accept, what do you do next to build a relationship?

1A. If your answer is "interact with their posts", what are the kinds of engagement that NTs see as "authentic" and what seems "scripted"?

1B. How do you make relationships not feel transactional?

2. You're networking in a semi-formal setting: a friend has set up an introduction with someone who could be professionally useful, but it's also slightly casual. They know you're job-hunting. What expectations do neurotypicals have of this conversation?

3. In-person networking events. How do I seem friendly without making it seem forced? What makes a conversation feel "natural"?