about memory

hello please can u help me i have this new iphone and i have still about 50GB free i dont know how but some of my photos and videos are on icloud 5GB memory but i dont wanna use icloud memory until i have this 50 gb , and i cant put it back on iphone please can you **** me how to put that 5GB of photos on my iphone without delete it? Coz evey time i make foto iphone say i cant coz i have full memory