Repent to Allaah, and then feel happy and be hopeful that He has forgiven you and don't repeat it i.e., watch out for unintentional lapses.
Also increase your knowledge of Tawheed and aqidah and of islam in general by reading books. This also may be a means of showing the sincerity of your repentence to Allaah-that you wish to avoid shirk in all its forms and so you are gaining knowledge for that.