I have these weird light brown spots under the breasts and on the upper stomach and neck. what could they be and how do i get rid of them?

Fungal infection: More than likely you have a superficial fungal infection called tinea versicolor. Treat with otc antifungal creams such as lotrimin or micatin (miconazole) twice daily for four weeks then retreat one day a month to keep it from recurring. If this does not work see your dermatologist.

Several things: What you describe could include a number of things from seborrheic keratoses to acanthosis nigricans to several other things. I would recommend you have a dermatologist examine you to help clarify what you have.