Writing your own random number generator can be a lot of fun. Lots of sources of entropy out there. Inspired by lavarand[0], I wrote an RNG in Python based on the output of the Global Conscousness Dot[1] (which is a ridiculous project in its own right). There's a lot of ways to visualize and ascertain how "random" your numbers are as well, whether plotting Pearson's with matplotlib or using a command line tool like ent[2] to calculate the degree of entropy.
[0] https://en.wikipedia.org/wiki/Lavarand
[1] https://gcpdot.com/
[2] https://manpages.ubuntu.com/manpages/bionic/man1/ent.1.html