Are you looking to apply for classes starting in the fall of 2022? If you are, there really isn’t very much you can do to improve your profile or chances at this point. Now is the time to be working on essays and applications and putting effort into school work, not the time to be looking to add more things to your profile. ECs are evaluated in terms of length of commitment and accomplishments.
Your best bet at this point is looking for schools where you have a better chance of getting in and getting the financial aid you need. If you have an idea of what your family can afford to pay, then we can see if you need to be looking for merit aid (which will not be available at top ranking schools).