If you want momentum, I'd suggest coming up with some ideas for individual superheroes now and worry about world building details later.
Here's a couple ideas I'm willing to throw in the pot:
Cameron Carmichael Caruthers is a former Navy soldier who was technologically modified for deep-sea operations: he can breathe under water, withstand the high pressure and bitter cold of the ocean floor, and use echolocation to observe his surroundings. Coupled with some enhancements to his physical strength and reflexes, he's a formidable aquatic warrior. However, his physical enhancements require battery replacements every so often to remain effective, otherwise he's reduced to the level of an invalid.
These batteries aren't cheap, so "Deep C" Caruthers has taken to doing very dangerous and not-quite-legal salvage work to keep himself afloat. He complements his aquatic abilities with a small submarine he picked up that, when he needs it to, can become a Humongous Mecha
for him to pilot. The most expensive quarry he goes after are pieces of alien technology that sunk into the ocean, but he'll also salvage stuff from more mundane shipwrecks, and even transport cargo or passengers if the pay is right (and if the pay is
right, it's usually because what he's transporting is likely to be attacked by pirates or customs officials).
Since a lot of his work falls outside the law, he sells most of what he finds at the floating city of Galtopia, created by one of those obscenely rich anarchists who wanted to make their own country free of all laws and government (though said rich anarchist still wields immense power, natch). In Galtopia, Deep C has gotten a reputation for his Chronic Hero Syndrome
, and can often be roped into helping someone even when there's no money in it, though he'll gripe about it all the way
Jane Wills was born with the psychic power of astral projection: when she's asleep, her dream-self manifests in reality and can interact with the physical world. Because this astral projection obeys the logic of dreams rather than reality, it is immensely powerful but also prone to causing destruction with its random, nonsensical behavior; Jane has been relentlessly trained to control herself and behave rationally even in her dreams
But one day, other astral projections start showing up all over the place; some are malicious, but even the well-meaning ones can cause lots of trouble due to their erratic behavior. Jane eventually deduces that a scientist who once studied her psychic power has found a way to replicate it in other people, resulting in these other astral projections who don't have the self-control she has.
Jane takes to fighting the other projections under the code-name Lucid, partly to stop the trouble they're causing, but also so she can get info from them on the scientist who gave them her power. She feels responsible for her power causing so much trouble, and is dedicated to finding the scientist and stopping his mad experiments.
What do you think?