This is a reflexive verb, which means that the "se" must match the subject. In this case the subject is "yo" which means that you must change the the "se" to "me." The "me" will go directly after the subject and before the conjugated verb.
You will then conjugate the verb normally (I am going to assume that you need it conjugated in the present. If not let me know)
Yo me ducho por la mañana.
This sentence says:
I shower myself in the morning.
Hope this helped!
~Just a girl in love with Shawn Mendes