In other fanfictions, they could be rivals. Goku is always looking for a strong opponent, and Sailor Moon's unique powers could make her an interesting rival. They might have battles where they test each other's limits, but also learn to respect each other in the process. They both have strong beliefs in protecting their worlds and those they love, so even as rivals, they could end up on the same side when a greater threat emerges.
One common theme is the clash of their different power levels and abilities. Goku is super strong physically with his Saiyan powers, while Sailor Moon has her own unique magical powers. Writers often explore how they would work together or compete in battles.
One interesting story could be a crossover where Goku and Sailor Moon team up to fight a common powerful enemy from both their universes. Maybe an evil force that combines the dark magic from Sailor Moon's world and the powerful villains from Dragon Ball.
There are probably some good ones. Some fanfic writers like to explore crossovers in a more family - friendly way. They might focus on how Goku's power and Sailor Moon's magic could interact in a non - violent or platonic scenario. You could also try looking for fan - made communities dedicated to these two series where they might recommend clean crossovers.
An interesting plot could be that Goku and Sailor Moon meet during a multiverse tournament where representatives from different anime universes are competing. They initially don't get along because of their different fighting styles and beliefs, but as the tournament progresses, they realize they can learn from each other. Together, they face off against a cheating opponent who is using unfair tactics to win. Through their combined efforts, they not only defeat the opponent but also learn to respect each other's worlds and ways of fighting.
Well, Archive of Our Own (AO3) is also a great place to find goku x sailor moon fanfiction. There could be stories where Goku teaches Sailor Moon some of his fighting techniques, or vice versa, which makes for an interesting read as their power systems are so different.