I can't remember if there are official tutorials, but some resources you want to have a look at are the blog posts of Zhe Wu: https://blogs.oracle.com/author/alan-wu
Look at the old ones as they cover things about how to start if not wrong.
You can also look at Creating a Property Graph on Oracle Database — Vlamis Software Solutions for blog post covering from A to Z a use case.
I would say it highly depends on how you want to do things. If you are using an Oracle Database and want to use graphs in the database itself or want to go for a standalone PGX.
I was supposed to write a lot more about how that topic but so far had no time, maybe still worth a look in case: https://gianniceresa.com/category/graphs/
If you don't have an environment you can maybe have a look at this docker image: https://github.com/gianniceresa/docker-images/tree/master/Zeppelin-PGX
It is based on a old version of PGX, but I'm quite sure it still work with the newest one too.
There is also Cytoscape with the Oracle plugin which can be interesting.
Last but not least: if you say a bit more about how you would like to do things (by code, interactively, visually etc.) it will be easier to give you hints.
For sure you will have fun