If I lose weight will the stretch marks on the sides of my stomach go away?

No. In fact, if you lose a lot of weight quickly they actually can get worse. Unfortunately, there are not any really effective treatments for stretch marks. Over-the-counter remedies like cocoa butter don't work. Laser treatments may help to lighten red or dark stretch marks. Fortunately they do tend to fade on their own over time.
Stretch marks. Stretch marks are a tear in the skin. Losing weight can help reduce the visible width of a stretch mark. Lasers can not repair stretch marks but can make them appear tighter, similar to the color of your skin, and improve it texturally so it is less obvious.