I looked up the computer on youtube to see what kind of motherboard you have and how big the case is. I think grabbing an SSD is a must, storage size is up to you but try not to get any fancy like Samsung 960EVOs or any m.2 ssd's because I don't think your motherboard supports m.2 ssd's. As for the graphics card you can easily get away with a 1050Ti or a 1060 3GB, they will both feel like a great boost in gaming. I believe your case is not that big so getting any 3-fan GPUs is actually risky since they might not fit in the case. Do some research though, I couldn't find what kind of power supply came with the system so just make sure that it has at least 300W.