Brand: It’s a Corsair forum, they have a good rep for mice.
Wired/wireless: high end wireless mice are ok for gaming, lower end ones can suffer from input lag, unless you play fairly competitively it is unlikely you will notice anyway. Wireless also has to be charged etc obviously.
DPI: a red herring, mainly used for marketing. It basically makes the mouse more sensitive to your movements. Most modern mice go to dpi settings which no one uses (or would want to) and many competitive gamers use low dpi settings to steady their aim. What does matter is the quality of the sensor, most modern med/high end mice have great sensors.
Pad: definitely recommended, it’s a consistent surface which is designed for glide and accuracy, a bit subjective as to what pad though.
Pick a mouse you like the shape of and has the features you want, try to figure out what grip you use and your hand size then read some reviews.