Go on YouTube look up builds. And make your decision, it will always be better to build it yourself (imo) because you can take the mark up of a prebuilt and buy better components.
My first pc I bought prebuilt.
My second one I built for less and had better components
7K is a lot of money, you can buy a 1080ti, 32 gigs of ram, and a ryzen 7 1800X or intel 8700K for 2 grand, once you start buying other expensive items you are really entering the "diminishing returns" zone, where you spend a lot of money and hardly get any more performance
Never too late to get into it man, it's super simple if you take your time and be patient, and worst comes to worst you can always have someone experienced look into it for you