This is a great question. There are several things that you can do. If you are in tenth grade, then you have a little time. I would say that you do the following:
First, you should try to read as much as possible if you do not. This will help you in your reading comprehension. Also reading will make you smarter.
Second, you should memorize the most frequent words that are used in the SATs. There are list that many testing companies have made.
Third, you should review your basic math. This will help tremendously in the math section.
Finally, if you have time, you should try to take a course. But first check with you school. They may offer one for free.
In any standardized test, such as the SATs, the best way to study is to do practice exams. If you did one practice exam a week with a follow up with what you did wrong, then your score will increase greatly. There are several benefits in this approach.
First, you get to feel what the test is like. This will mentally prepare you to take the test. In other words, when you take the test, there will be no surprises.
Second, you will also get a feel for what kinds of questions the test creators ask. You have to realize that most of these test are just recycling old question with different wording. This is especially so with the math section. So, if you get a hang of the types of questions that are asked, you will do well.
Third, you will also find out your weaknesses. If you consistently do poorly in one area, you can focus on that area. In this way, you will become a more complete student.
There is no better way to study for an exam than to practice.