Preparing subfloor for engineered wood

Hi - I would like to understand what needs to be done in order to prepare the subfloor I have in my apartment for a nice engineered wood flooring. This subfloor is quite old, not level, has traces of glue on it, and I'm struggling to fully understand what I need to so. I attached a picture here which might help understand what I'm talking about. Ideally I want to put something on it that will protect the new floor and protect me from noise as well, and I want to correct the floor leveling so it's flat. If I just put plywood I'm worried it won't help with noise reduction. Also consider the variations in height of the subfloor, installing plywood is going to be a mess. Thank you in advance for your help.