Question New parts and confused

Dec 27, 2019
Hello I recently bought a very cheap gaming pc for 50 bucks and am upgrading it to learn more on computers as this is my first ever computer. I have installed a ryzen 2600x cpu a b450m ds34 motherboard and 16gb of ram. The pc is running 10x better than it was with the old cpu. My issue is before doing this I was having lots of memory issues as I only had 8gb and play fortnite a bunch so when upgrading I moved up to 16gb but for some reason my memory is still hitting 90 percent or above. I've double checked the ram are in the right slots just not sure if I have to do something in the settings or should I buy a new ssd as that is the only thing left to upgrade aside from the case. The only other thing I could think of would be while assembling the pc i ran into 2 cables that had the same connector plug is it possible I plugged them into the wrong place as each had two slots they would fit in