Highly recommend Go, especially for that realm. Building something else that already exists can provide a good roadmap and reference for how things are / can be done.

You could build a server, but I'd personally find something like https://nats.io (messaging) https://fission.io (serverless) or https://redis.io (cache) more interesting. You might also look at the Kubernetes ecosystem. Building a tool or service that can interact with the API can lead to new opportunities (people hiring specifically for operator experience). I work on a code generation tool (https://github.com/hofstadter-io/hof) and https://github.com/cuelang/cue

Go's source is also pretty interesting and full of great things (https://github.com/golang/go). Here are some of the internals pulled out: https://github.com/rogpeppe/go-internal