once you get situated in school and pick a major, you'll be able to take some advanced courses in that major and be well versed enough to actually do some intro level research. it's a good idea to figure out what you like first, then go seek out research positions. it's great that you're so motivated, but it's too early unless you know exactly what you want to do (ie. chemistry/physics/biology/etc) you need to have a discipline down.
to answer your second question, when you do an experiment for a number of months and you collect data and analyze the data. you get results. if these results are meaningful, you can send them to a journal (all disciplines have their corresponding journal(s)) and have them take a look at your work. if they think it bears merit, they will possibily publish it in their journal. it's a big deal to publish, IMO, cause that publication sticks with you for the rest of your life. whenever you go to the library and type your name in, you are listed as an author of something that was published. pretty cool huh? i just published a paper in the journal of neuroscience methods which i worked on for a year.. it's a great feeling!
good luck!!!