What types of entering jobs would be best for someone who's interested in business/fashion to have more experience?
I share that the closest I have gotten, professionally, to fashion is looking at pretty pictures :)...but the business side, I know a little bit more about..
More broadly, businesses will be successful if they are able to grow financially. One aspect of that growth is to keep costs as low as possible without sacrificing the quality of the product. One of the things I encourage you to become aware of is costs to create. Gain an understanding of costs related to things like employees, designers, materials, shipping, advertising. What does it cost if something is delayed? Is there a cost benefit (or is there less of a cost) to getting something created sooner than expected?
Whether it's fashion or some other business entity, there will always be a need to understand what causes costs and how to keep costs at acceptable levels.
Hope you find this answer helpful and best of luck to you!