This is my first build! I'm using it for AutoCAD, photo editing with Lightroom, and some gaming (Forza, Destiny 2, Battlefield).
I went with the Ryzen 5 1600X because it was in a good deal bundle at Newegg, or at least I thought it was at the time. Pretty good clock speed and lots of cores, which so far has been really good for me.
I got the Asus B350-F AM4 motherboard because I needed the USB 3.0 ports.
I went with the EVGA 1070 because Forza.
The Noctua NH-D15 AM4 cooler supposedly fits in the Corsair 450D, but I had to readjust the front fan on the cooler a few times in order to get the side of the case to sit properly.
Feel free to ask questions or comment below. Go easy, it's my first build.