From what I know as of the end of last year, you didn't need a license to wholesale real estate in California.
Wholesaling is 70% sales and marketing, so I recommend consuming related content. Chris Voss's negotiation course was beneficial for me. If you're looking for a real estate book, I highly recommend "Estimating Rehab Costs" by J. Scott.
And can you guys recommend me on how to get into the wholesaling game and how to learn (Books, courses, etc....)
No you do not need a license to wholesale real estate. The best way to learn is to get your hands dirty. Make calls, fail a 1000x, until you carve your own path.
There isn't a book that will lay a roadmap and get you the success you need. If not everyone would be rich.
You don't need a license, but like any other business, you would work with someone who is experienced. You don't want to mess with seller's lives and make their lives more complicated.