One important question is do you know how the scratches presently on the car showed up? Because let's say you bought the car and took it through the tunnel wash. That's where they came from. And if you fix the scratches but go back to the tunnel wash, they will come back.
So from now on, are you willing to carefully hand wash the car and never let others wash it? Do you already own the products that will be needed for that and know the proper technique?
Once you know you'll be able to keep the paint looking good, then it's time to make it look good. All suggestions above are great. If your paint is on the soft side it won't be too much trouble but it could end up being more than you expect and since you need a handful pads of each color, you could find yourself ordering a dozen pads, perhaps more to get started. That's fine if you plan on using them again and taking care of your current/future cars. But if you're not going to use them again, the investment might not be worth and it could be better to just pay a pro to detail the car for you and be done with it. A machine and pads and products will easily set you back a few hundred dollars.
If you want to learn this is the right place, the crowd here is nice and will help you.