Occasionally someone tells us that they got an internship while they were in high school ... but it doesn't happen often. Try smaller local companies that manufacture clothing or retail stores .... things like that. Smaller companies probably don't have the rigid requirements and if they like you, they might take you on for a couple of months. Of course, you'd probably have to find the time during your school day to do this.
In some states they have something like Regional Occupational Programs (ROP) in the high schools which allow high school students to intern in certain businesses in lieu of a couple of classes ... so you might look into that. Do you have counselors in your school who help with things like that?
Also, check this thread ...
Fashion Career Building Activities if you are Still in High School which is about other things you can do to build experience to add to your future resume, while you are still in high school. And this one, if you are planning to attend a fashion school in the future ...
High School Students, How to Prepare For Fashion School .