Youre a junior now right?
You can take the ACT/SAT's again over summer or even in your first quarter/semester of senior year. Then if you get a better score you just submit it to the college and theyll make a desicion based on that score. Even early desicion application deadlines, which im not sure if thats what youre going for, isnt until like October or november for most schools if i remember correctly. So i dont think you have to apply over the summer, that seems wayyy earlier.