My mom kicked me out of the house almost 3 months ago and I'm only 15 and she has full custody of me.. what should I do?

Go to the Police, tell them you are (basically) homeless and without financial support.

They will investigate and find a foster home or similar place for you to stay as you are a minor.

Has your mother filed with any Court to declare you either in need of supervision or to attempt to emancipate you?

What exactly do you want to accomplish at this point? Get back into the house? Find somewhere else to live? Get financial assistance?

I agree with Judy, except for one point, Rather than go to the police I would go straight to your local Family services center.

What have you been doing for the last 3 months?

my mom kicked me out of the house almost 3 months ago and im only 15 and she has full custody of me..what should i do??

Where have you been for the past 3 months? With your father possibly?

Why did you get kicked out of the house?

There are too many parts of the story missing here.