I wrote one on setting up graphite on rhel8 a while back: A distro agnostic guide to Graphite with venv (examples: RHEL8, Debian10, Ubuntu18)
I’ve actually switched to InfluxDB and the Grafana module since then, though. I would say InfluxDB is a far superior TSDB to Graphite (my opinion), but the Grafana module for Icinga is going to take more levels of configuration than Graphite’s (which kinda just works). If you’re stuck somewhere, let us know and we should be able to guide you.