Layering an overshirt, general advice for looser fits

Hey guys, so I came across this reddit post that was great for inspo, so im trying to sneak in a few pieces in my wardrobe to progressively learn "how to dress" like this

https://www.reddit.com/r/malefashionadvice/comments/gjrd22/how_to_breathe_an_album/

I got an overshirt, specifically this one, that i got for a great price (carharrt wip arden, first picture):

and some black pants like the second picture

im trying to figure out what to layer it with, anyone got suggestions?
thought about a hoodie maybe