Do small, but good things, that nobody else sees. Pick up trash, fix something, let someone in front of you in traffic, smile and thank your cashier, hold a door for people, give a $5 bill of to an old person panhandling, etc. You will know you are doing positive stuff without credit, and you YOURSELF will recognize that you are a good person, and that will change how you want interact with everyone else. Eventually others will recognize it, too.