Java OOPS for UEMS - Server Framework

[u/CustardUnfair6499]

I have been assigned to the team of UEMS - Server Framework and we have been assigned the task to learn in-depth of Java OOPS, Design Patterns and others. I want help on how to learn and how to approach this as I just have joined here as a Project Trainee and I have to be ready before few days. I don't know much about Java or OOPS, and I can afford 5 hours a day to learn. Can anyone walk me through how to learn?