This verb is usually used reflexively since the subject is most always receiving and doing the action. In other words: I’m going to take care of MYSELF; She’s going to take care of HERSELF.
Whenever you can “hear” the myself, yourself, oneself etc that’s your cue to include the reflexive pronouns: me, se.
Se cuida. Take care (of yourself).
Eu sei me cuidar. I know how to take care of myself.
|I take care of||eu cuid||o|
|you/he/she take(s) care||você/ele/ela cuid||a|