The grammar topic "reflexive pronoun" is not one of the most complicated in learning Russian. But as teachers we can see that a lot of students make mistakes using the word "себя" (the only reflexive pronoun in Russian).
"Себя" universally means "oneself"/"myself"/"himself", etc. It is inflected depending on the case. When used to indicate that the person is the direct object of the verb, one uses the accusative form, "себя". (It does not have a nominative form.)
Он видит себя. - He sees himself
Often we use emphasized forms. We need to add the word "сам" (сама, само, сами). "Он сам себя сделал" (He is a self-made man).
Good luck in learning Russian!