Search right here, in Oxy-Faq. We try to update it frequently.
Search in the Official Oxygen Facebook Group: the search engine is not the best but you still have a high chance to find the answers you are looking for.
Still can't find answers? Go to the fantastic collection of Oxygen stuff made by Simon Kress (subscribe to his awesome newsletter): the most convenient way to find tutorials, resources, snippets and so on...
Your question is not related to Oxygen but still about WordPress
Google will be more helpful (or any other search engine).
Your question is not related to Oxygen nor WordPress but it's more about Code (CSS, JS, PHP…COBOL?)
Stack Overflow is often the best place for that.
Your website is broken probably because of Oxygen (most of the time it's not but you are not sure about it)
Don't wait, contact Oxygen support, especially if it's urgent: https://oxygenbuilder.com/support/
And it can be useful when you think you have discovered a bug to check the official list of bugs...
And finally, don't forget to check the Trello board created by Amanda Lucas and updated by the community, for more resources : https://trello.com/b/t048TPPM/oxygen-builder-resources
Some other resources: