If you translate these sentences word for word., you can say "난 신경 안 써 or 난 상관 안해." However, these sentences in Korean sounds a bit you are upset at somone. So you'd rather saying 난 괜찮아 which means I'm okay. If you have more questions about it, put your comment down below.Thanks

"I don't care" and "I don't mind" in Korean : 난 신경안써, 난 상관안해, 난 괜찮아

감사해요 ㅋ

To be more politely, "난 신경안써줘도 괜찮아" which is a nuance like "It's okay for me, so you don't have to worry about me but thanks for your care."