Review the sentence:
Walking into the tree, Kareem's old, holey shirt was ripped, and his
forehead got banged.
Walking into the tree, a participle phrase, comes right before shirt, an illogical target. Kareem, not the shirt, is the one with legs that can walk! (Kareem's, a possessive noun, functions as an adjective, as do old and holey, describing shirt.)
Before you continue, review the rules for misplaced and dangling modifiers.