Hello, and welcome!
Online, your best resource on OpenBSD will be the
FAQ. Much of the information available from third parties may be out-of-date or might be misleading in other ways.
(I include us in that list of third party resources. If you find guidance in a thread here, check how long ago it was posted. New information may be available.)
Offline, the best resource will be
Absolute OpenBSD, a book by Michael W. Lucas. There is a recently revised second edition, and it is an excellent resource. The first edition was a primary resource for me for ten years, and the new second edition is proudly sitting next to the first on my shelf.