You get a composite score between 1-36 which is the average of your individual scores from the English, Math, Reading, and Science sections. On each of those 4 sections you can score between 1-36.
There are 5 scores for the optional writing test. There is a Writing Score and 4 Domain Scores ranging from 2-12.
There are strategies that we at Expert Exam Tutors, LLC teach you to use the scoring system to your advantage in terms of how you approach answering certain questions.

Two weeks is the general timeframe to access your scores for the multiple-choice questions, as well as the composite score. You will need to go to your ACT online student Web account. Additionally, they will notify you when the score for the writing portion is ready.

That’s highly unlikely. We will work with you in advance to practice relaxation to calm your nerves over test taking. But take a deep breath. You can take the test over if need be.

There’s no magic number. It’s a good idea to take it initially in your junior year to give yourself time in case you want to retake it. You can decide to take it again and choose which test scores you want to send to colleges, universities, and scholarship programs. One caveat though to avoid lowering scores, it’s advisable not to continually take the test without working to improve skills in mastery of the content and adeptness at implementing test-taking strategies. Working with our tutors helps alleviate this problem as we focus on enhancing ability in both content and test-taking skills.