It is hard to say. Even with a 3.75 high school GPA WUSTL is a very high reach, and Princeton is even less likely. Having problems during your senior year of high school is not the best timing, although the pandemic impacted a lot of students and was tough for everyone. Even one student who I know who managed to keep their straight A’s though the pandemic has told me that it was very tough.
If you do not apply then you cannot be accepted. However, WUSTL and Princeton look like very high reaches right now. Another year of strong grades in college will help your application quite a bit. Even with this, if you are serious about transferring (which I assume that you will be eventually if you are at community college and getting straight A’s) then you will want to apply to a range of schools, including at least one or two where acceptance is very likely.
This is also hard to say. You do not want to sound like you are making excuses. “This is why I am now doing better and will continue to do better” should be more the theme. I have heard that it is generally better to have an advisor who knows you (such as a guidance counselor) explain extenuating circumstances. However, this is not an area where I have much experience. There are good universities that will give a chance to a student who has shown strong improvement. However, WUSTL and Princeton are at a level where they get a long list of applicants who have nearly perfect records, which makes them a high reach for everyone else (and a reach even for the students with nearly perfect records).
By the way one daughter had a friend who was among the strongest students in the middle school, and then in high school, but for financial reasons started at community college. After two years of straight A’s in community college she transferred to a local public university with a full merit scholarship. She ended up graduating university with a very high GPA and a very marketable major. Just by chance I happened to run into her in a store about one month before her graduation and she was doing very well and had a big smile on her face. I am quite sure that her father, who I had gotten to know very well through school events, was very proud of what she had accomplished. It is possible to do very well in community college, transfer to a good university, and continue to do very well.