As a user of Timescale, one of the things I find most lacking with Timescale (and postgres also to be honest) is good educational content on par with MongoDB University; structured courses that teach you database design concepts from first principles and then what problems postgres/timescale solve on top of them. Hands on experience working with datasets and an interactive way of learning more about the types of things you can do.

I realize Timescale and Mongo are very different things, but when I got professionally started with software 10 years ago, the MongoDB courses (and the stanford online Intro to DB course) were immensely helpful. Working with Timescale professionally now I'm often unsure whether I'm doing things suboptimally, e.g. making tables hypertables when a regular table might be better, flexibility and capabilities of indexes with hypertables, and application-facing tooling.