Only spend money on summer programs that make sense for you- the summer programs that will impress AOs are not the ones you have to pay for.
Read this- it’s from MIT admissions, but it applies just as much to NU:
Figure out what, exactly, it is you want from NU (more than just liking the idea of living in Evanston/being part of that community). You may be 100% gunning for NU now, and it is possible you won’t change your mind in 3 years, BUT it would be irrational to only apply to a school that denies 91% of applicants!
So first, figure out your budget. Then, think about what you see as the best things about NU and work on finding other schools with at least some of those characteristics. For example, if journalism is key for you, UIUC is a great in-state option and Syracuse is a great private option (if affordable). Can you afford Kenyon’s amazing creative writing program? and so on.
Lucky you, even if your school doesn’t have much in the way of ECs for you, as writer with internet there are a world of ways for you to have really interesting ECs! Collegekid1 was a paid blogger in HS & college for an organization in her field of interest. Collegekid2 was regularly involved with creative writing outlets online, and ended up winning some nice prizes. And so on. It’s not that it will be easy to find a good path- it’s that it is possible, and as it is something you really enjoy the journey can have some fun parts as well as the sloggy bits!