As someone who will most likely just meet the average GPA requirements, what should I do to really stand out?

There are a number of ways to make your application stand out in a genuine and effective way!

It helps if the entirety of your application (ECs, essays, letters of rec, courses) conveys a strong narrative about who you are. It is important to not explicitly state this story, but to weave it into every aspect of your application. For example, if creativity central to your identity, this characteristic could be communicated through what activities you participate in, how you write your essays, and what your LORs say about you. Try to give admissions officers the opportunity to discern integral aspects of your personality and how you would fit into their campus just by ensuring that a relevant central theme is maintained throughout your application.

Communicate genuine interest. Supplement essays are usually a great medium to do this. Make sure your reasons for wanting to attend a school are well-researched, specific, and unselfish. Think about what your academic interests are/why you have these interests and research how you will be able to explore them at the schools on your list. Admissions officers can detect insincere aspects of an application.

In terms of action you can take now related to ECs -- think about where you genuinely want to invest to your time. What interests you? What do you want to learn more about? What do you want to contribute to your community? Once you have a clearer idea of what would be meaningful to you, look into the ways you can pursue this work. Maybe it means joining an existing organization that aligns with your objectives (many have virtual opportunities), or maybe there is no accessible existing organization that sufficiently represents your interests so you decide to start your own.

Colleges generally like to see a mix of breadth and depth when it comes to ECs. Consider focusing on two to three extracurriculars that you can fully commit to and display leadership in but highlight different attributes of yourself!