Well, it'd be a wild ride. Imagine Goku encountering characters like the Avengers or the X-Men. His Saiyan powers might cause chaos or he could become a valuable ally, depending on the plot.
It could lead to epic battles and team-ups. Goku's super strength and energy attacks would mix with Marvel's heroes and villains in exciting and unpredictable ways.
The possibilities are endless. Goku's arrival in the Marvel universe could trigger all sorts of storylines. Maybe he'd face off against Thanos or train with Doctor Strange. It'd be a mash-up of epic proportions.