This link is to some guides I prepared when Hangouts Online disappeared. Some of the details may have changed since then (for instance, StreamYard now only allow 20 hours in any month under their free option), but these should be enough to allow you to experiment:
https://drive.google.com/folderview?id=1puGkdsVe0ZwHdPHbi5pKAJTaFZWRQIXf