I'll be whatever person I like thanks.
And most open source software starts as a one person job. And as you approach something that other people see the value in, you'll likely attract people who will help.
For the most extreme example, see the Linux Kernel itself.
Someone has to start the ball rolling, and if it's something you want, it may as well be you.
A null does not make it memory unsafe. You aren't accessing invalid memory, the runtime just raises a NRE. Which is fine. No memory safety violated.
Java is, as long as you stick to pure java and not native interop, entirely memory safe. And that's achieved by giving up control of memory allocation to the garbage collector.
Rust is not the first memory safe language. It does however, manage to achieve memory safety without needing a garbage collector. Which is what drew my initial interest.