You aren’t going to meet everyone you need to in your office or online. Go more places where engineers congregate. Travel. Go to conferences and training programs and get to know people while you are there. Talk about yourself and learn more about them.
Every single person you meet could help you later. Take a little time to get to know them. Show an interest in who they are and what they do and they will likely do the same for you. Go out of your way to impress everyone.
Well… not everyone. You only have a limited amount of time and some people really are more important than others. If the CEO of an exciting startup wants to have lunch you can prioritize them higher than a junior engineer. Just remember that everything changes and the junior engineer you know today might be the senior architect you know in five years. Prioritize people when you have to, but don’t dismiss anyone.