Joined some entrepreneurship seminar. It was useful. Just overpriced. There was a Facebook group for participants.
My cofounder was selling ebooks on business advice in that group. He wasn't particularly famous but offered a 100% money back guarantee and the books were like $5 anyway. They were good advice, some of which I still quote today and get a bunch of upvotes for on HN lol. He had some Facebook groups of his own. We'd post about these kinds of things, as you do in HN today.
One day, after struggling with trying to find employment and freelance clients I decided to just make an app company. I wanted to do e-commerce, figured I needed a partner who had experience with the offline part. Since I was buying books on logistics and stuff from this guy, I offered to meet him and pay for his latest book, but instead of paying cash price, I'd pay for a meal that cost more than the book. He was happy to meet. We clicked. Built a startup and sold it for decent profit after a year... we did run out of money and it was easier to get acquired than funding.
I know YC says don't do businesses with strangers off the internet but it works for me. Dude was really ride or die, and stuck through the lowest lows. Heck I met my wife by sending SMSes to strangers, but that's a story for another day.
I really think the be a founder with someone you've known since kindergarten and who went to the same uni and you are best friends like brothers thing is a bit overrated. Find some random. Do some lower stakes work with them. See if you like them; share values; etc.
You know that dating thing and then some dates lead to marriage, kids ... like what has kept humanity from going extinct. Yeah it works. Same with trade!