Knowing what you want is one of the most important, and often challenging, parts of the recruiting process. The classic quote from Lewis Carroll's Alice in Wonderland certainly applies here: if you don't know where you're going, any road will lead you there.
You need to know, or at least have a good sense, what you want to happen during your recruiting process. This doesn't necessarily mean that you need to know exactly where you want to go to school right away, but you should try to have an idea of what you want to accomplish during high school and within your sport. And you need to be sure that your motivations and preferences are driving the process, not those of the coach who is recruiting you.
So, all of the info above is helpful and good to keep in mind, but it doesn't actually help you with the how.
What can you do to help you identify what you want?
Start by asking yourself the following question: if I could choose, right now, what school to attend, and I knew that I would be granted admission and a spot on the team, what would I choose?
Of course there are a few caveats and provisions to keep in mind. You have to be somewhat realistic with yourself. If you're a second string football player in New England, saying that you want to play for Alabama doesn't mean that it is hands-down the right school for you. At least not if playing football in college is truly important to you. Similarly, if you struggle to maintain a 3.0 unweighted GPA, setting your sights on Yale might not be the best strategy.
However, there are several pieces of information that you might be able to draw out of the Alabama answer. Maybe this means you want to go to a large school, where athletic competitions are widely supported and attended. Maybe this means you like the idea of getting out of New England for college, experiencing a different part of the country.
As you can probably tell, the second level question is why was this school my answer? what about it do I find appealing?
Even if you haven' t visited many schools, the line of thinking outlined above is still helpful. Being honest with yourself is hard. It also gives you the best chance of attaining what you really want. You owe it to yourself to be honest and give yourself the best chance of getting what you really want.
It's much easier to get over a disappointment than a regret. Please do yourself a favor and don't leave yourself regretting not going after what you really want.