How do i secure my apartment before I move in?

Ok, im planning on getting my first apartment for when im in school this fall and next spring, and financial aid will give me enough money for rent. however, my school do NOT disburse the refund checks until the first week of school, and I plan on being in my apartment by then. So i was wondering how would I go about doing this? im currently working right now so I can have money for the security deposit. and i am also tryin to save up for first months rent myself for august since i will not get the financial aid refund check until maybe aug 31st or first week of sept. but im wondering if i can like pay my deposit and have the apartment people hold a spot for me until maybe mid august, then i can wait until the first of sept to pay rent with the refund check. but im uncertain as to how it works, so I would greatly appreciate any advice, thanks