I'd just clear space on your hard disk then do it with druid at the install, probably the easiest way to go about it. Don't forget to create a swap partition roughly twice what you have in physical ram is probably the best size for it not to sure considering I'm new to linux myself just started in January, dumped XP then.
If your mainly going to be playing games though you may find that in most instances windows is better for that considering nearly all games (unfortunately) are developed in DirectX over OpenGL. As far as sound editing and graphics goes I can imagine there should be some very good if not better apps than windows considering this is a more stable and efficient OS. Not one crash since initial install other than KDE whinning at me a few times I've been quite impressed to be honest.
Laptop: Lenovo ThinkPad T410, CPU: Intel Core i5 520M, Ram: 8GB DDR3, Hard Drive: 320GB, Graphics: Intel HD, OS: Windows 7 / Arch Linux x86_64
Desktop: Motherboard: ASRock Fatal1ty AB350 Gaming K4, CPU: AMD Ryzen 3 1200, RAM: 8GB DDR4, Storage: Samsung 850 Pro 256GB, Graphics: Asus Radeon RX 550 4GB, OS: Arch Linux x86_64