Capability Based Security isn't ready for prime time yet, despite being 50ish years old. Trillions of dollars could be made in that space.

There are vast areas up for grabs, in all directions. The best way to start is to build some little project that scratches an itch for yourself, and then share it with others in a community. There are so many virtual and in person communities out there besides the Show feed here on HN.

Nobody is too young, nor too old to be a maker of something cool.