Advice/What to focus on for next two semesters?

Hello right now I am a sophomore at a state University next to where I grew up, and I have been looking to transfer into a few institutions including Columbia for the past year or so. I haven’t applied to any schools and have been waiting until I am done with all freshman/and sophomore level math and science classes (Physics and Calculus 1-3) to transfer into a different university. The reason I want to transfer is because I want to get out of State and away from the place where I have grown up my entire life- and especially to make new and different friends and stuff. I also want to go to university that is more challenging and rigorous, because I know it will make me a better person in the same way coming here did a year and a half ago.
Anyways right now my GPA Is 3.8, and I have been taking progressively more difficult courses each semester. (This semester is Physics I, Calculus II, Genetics, Organic Chemistry, Metaphysics, and Physics Lab). I am also a teachers assistant for the department chair and I have a research project I have been working on with another professor for the past few months, which I am hoping to complete by the end of this semester.
This past summer I did a web design course at Yale and over spring break I am going to try and find an internship for this upcoming summer.
Next year once I have finished Differential Equations and Physics III, I am going to apply for fall transfer into maybe 7 or so different schools, with my top choices being Yale and Columbia.
I am making this post because I am hoping to get some advice as to what I should be focusing on for the next year of my life? Right now I feel like I have basically peaked in the amount of responsibilities I have on my plate, and am do not feel like I have time to join any clubs or get involved anywhere else, as at this point I really just need to focus on my classes and maintain my GPA.
Another thing to mention though is that I also have two years of bad transcripts at my local community college with quite a few withdrawals and a 2.4 GPA. I also have a 28 ACT and a pretty poor high school performance. but I had figured that most of that would be overlooked if I can continue to succeed in STEM courses.
Like I said. At this point I am basically just trying to keep up with my courses and work on my research project in my spare time, and I so am thinking it is just a matter of discipline and focus for me to accomplish my goal of transferring into one of my preferred Universities. Lately I have just been very anxious about it because it is something I have been focused on for what seems like forever now and I am about a year away from when I actually start doing my applications.
So I am just hoping for any insight, advice, criticism or otherwise that may help me in my situation because I could definitely use it.

Glad to see that you’ve turned things around. I agree that you should focus 100% on your studies. ECs and other things are good to have, but it shouldn’t come at the expense of your grades.

Getting into Columbia, or any of the top schools, for that matter as a transfer is incredibly difficult. Even though you’ve shown a lot of improvement, they will look at your past. So just do your best, you can’t really change the past.

If you’re interested in engineering, then you should look at the 3-2 program at Columbia. Best of luck!