All the maths that is taught in Secondary School is used in some area of the real world. Algebra and equations are used all the time by engineers, economists and scientists. If you go on to study any of these subjects at college or university you will find that your school maths will be your foundation for learning even more complex mathematics which is used in the real world.
However, one of the most important skills that maths teaches you is problem solving. If you develop skills which help you understand and then solve a problem, you will use these skills in lots of different areas of your life.
Of course, everyone needs to be able to add, subtract, multiply and divide to get by in the real world. The more confident you are at arithmetic, the easier your life will be!