Things you must find out for yourself, and then come back to us with:
What keys would you like? There are four main ones: Red, black, blue, and brown. All of the keys actuate at around 2mm -- so about halfway down from resting. What this means is that, as you get more effective, you'll only be pressing the keys about halfway down, instead of hitting the bottom. Red and black are "linear", in that they have no feel to them, just a smooth slide up and down. Only difference is that black has a stronger spring, and takes more force to press down. Blues and browns have a "bump" at the actuation point (which is around 2mm down, not all the way) to let you know you've "hit" the key, and can start coming back up. Blues are more of a "click" than a bump, and are very much audible, where browns are much more subtle both in feel and in sound. Typically, I'd say I hear more people going with reds or browns, with typist preferring browns, and gamers preferring reds. But ultimately, you need to get a keyboard in your hands and determine which you like -- a lot of people think they'll like one switch based on description, and find they like another entirely after using them.
After that, you need to pick your form factor. There's 3 main ones -- full layout, which is what most are familiar with, tenkeyless, where the numpad is omitted to save space, and finally 60%, where everything to the right of the enter key on your pinky is chopped off, and many functions (such as arrow keys) become Fn layer keys. 60% is a bit extreme, but a lot of people go for Tenkeyless.
And finally, your features. Lighting, macros, extra kebabs, all this should be your last consideration, as ultimately it makes the smallest difference to you in the long run.
After you've figured out what you want from those, THEN we can help you out lol.