This is my map of The Slums from STRAY. It was hard to be perfect so a few spots are off, but it should be easy to follow. I added in details that mark climbable objects to reach the roofs. Enjoy and leave a rating before you go :)

You visit The Slums a second time during your playthrough, and your inventory will be reset. I recommend finding all music sheets and B12 memories during one chapter.

Part 1 : All you really need to do is talk to Guardian, then Momo and gather the 4 notebooks.
Part 2 : Meow at Vapora, get the Detergent and trade Azooz for the Electric Cables. Take those to Grandma for a Poncho that you'll have to give to Elliot during the story.