So if you go to a conference once and you think it change your career... It won't happen. But it is an opportunity to ask your question to speakers or have longer conversation with them after the talk. If it is aconference close to where you live, look at the sponsors area. Maybe they have a section for local dev communities. Go speak with them, and try to join and be involved in your local community. Or maybe there is a speaker who is also a leader of the local user group? Go ask them about it.

But if you are really looking for networking opportunity, here is a tric. Every conference has a team of volunteers. I cannot recommend enough to go at conference as a volunteer. Different conferences treat it differently, but you have free access to the conference and you are not required to be on duty all the conference. So it is a free entry. But this is not the biggest benefit. It is actually that you are part of the team so you meet other developers, not necessarily juniors or students. The conference I'm volunteering at has healthy mix of experienced and junior Devs in the volunteering team. And there is one more benefit of it. If you are on the room supervision duty, you are assigned to a specific room. Use this opportunity to listen to talks which might be not your choice from the abstract itself. Which often is the best experience I have at conferences.

And people. After attending the same conference as a volunteer for the last 10ish years, I have many friends there and is one of the only few opportunities in a year to catch up

I also often meet there people I was working before with.

So if networking is why you go at conference. I would say try to select one close to where you live, where you can meet other people from your area.