This page lists out the current recommended steps to submit a patch as a New Contributor to OpenJDK. It assumes that you are making a fairly small change to core OpenJDK libraries, (i.e. Java code, as opposed to Hotspot C/C++/Assembly) for OpenJDK 9 or OpenJDK 8 Updates.
I NEED HELP! If you need help at any time don't hesitate to contact us at email@example.com or on the IRC channel (#adoptopenjdk on irc.freenode.net).
Read the Official Contribution Guide for OpenJDK.
I'm comfortable starting on my own
If you feel you are comfortable diving straight in, then simply follow the steps outlined in
I'd like to be guided through my first patch(es)