However I would like to know if you were aware of any sort of workshops and/or tutorials that I could access so that I can practice and learn lamdas and predicates. The more I know about them the better, but currently I'm more focused on the OCA 808 exam related topics.
“The strongest of all warriors are these two — Time and Patience.” ― Leo Tolstoy, War and Peace
IMHO, the most thorough way to practice with lambdas is to use a fully functional language. I don't know if you have the time or the patience to learn a whole other language, but if you do, check out Haskell. Once it clicks, you will definitely start thinking in terms of functions all the time.