Goku could escape by overpowering Broly. He might tap into his Super Saiyan forms, like going into Super Saiyan Blue or even Ultra Instinct if he's pushed far enough. His sheer power and fighting skills could allow him to break free from whatever restraints Broly has put on him.
Well, it depends on the fiction. In some universes where the power levels are relatively low compared to Goku's capabilities, he might be able to solo. But in many complex fictional settings with extremely powerful entities and various factors at play, it's highly unlikely that he can solo the whole fiction. For example, in some fictions with omnipotent or near - omnipotent beings, Goku's power would be no match.
In the manga, Goku does fall into hell as part of a complex and adventurous storyline. This event leads to many interesting developments and challenges for him.