Lil Peep wore a wide variety of outfits. He'd combine old, thrift store, and designer pieces. His style shifted frequently, and his most recent incarnation appeared to be punk (plaid pants, studded denim vests, doc martens). He once claimed that it didn't matter where he got his lil peep clothing because some of the coolest stuff he found was in petrol stations.
It's good to be inspired by him, but he was tall and had ideal proportions for design, so he could pull off ensembles that would look ridiculous on most people. The essential point is that he didn't like to dress like everyone else; he would follow specific fads (such as Gucci shoes), but otherwise would do things his own way.