Now that you're no longer a rookie, your job is to evolve as a learner. 

Refine your route: Look ahead to which 11th and 12th grade courses you might be interested in taking and plan to work in any prerequisites. 

Challenge yourself, but wisely: Create a balanced schedule. You want to strive for the best possible grades, but overtaxing yourself is bound to be counterproductive. Stressed-out brains don't work well. 

Get some practice: Will you take the PSAT this year? You'll get a better sense of where you stand if you know what is on the test before you take it. 

Also, consider whether an SAT subject test makes sense in the spring. If you're enrolled in an AP or honors course now, the timing may be good. The College Board makes practice versions. Take at least one. 

Put together a resume: Note your hobbies, jobs and extracurricular activities. For now, it's just a way to keep track. 

Make the most of your summer: Although lounging by the pool can be relaxing, it won't help you uncover your passion. Work, volunteer, play sports or take a class. Find an activity that builds on a favorite subject or extracurricular interest.