> It’s been told the best way is to reach out to classmates and co-workers. However, that seems severely limiting as I’m sure there’s opportunities outside of my personal network (especially since I graduated a while back).

One of the very important features in co-founders is knowledge of work-ethic and trust in each other. That's why it's often recommended that you co-found with people already in your circles. There are just so many additional unknowns when you're dealing with potential co-founders that you have no history with.