A direct object will typically follow an action verb and can be nouns, pronouns, phrases or clauses.
Example: John kicked Billy. The direct object is Billy because the kicking is done to him.
An indirect object is rarer and needs a direct object in the sentence in order for there to be an indirect. When someone or something gets the direct object, that thing or person is the indirect object.
Example: Joe made a cake for Jacob. The direct object is 'cake' and the indirect is Jacob because he is receiving the direct object.
Hope i helped :)