Making a budget is important (unless you're rich, in which case you can skip this or you already know this, which is why you're rich). But you should be aware of how much money you have coming in and how much is going out.
Budgets will also help you plan for rainy days when you need extra cash or to save for a vacation that you really want to go on. They are super-duper important. In today's hyperconnected world, there are a bunch of budget-planning apps that are easy-peasy to use. Start by exploring the App Store on your phone, and peruse the "finance" section to find one that works best for you.