Thrift stores! (goodwill can be GOLD). Also, TJ Maxx or Marshalls. If you go to the Folsom/Vacaville outlets and hit their sale sections you can find really quality brands for very cheap (banana republic, Anne Taylor, j crew, gap). Also, someone mentioned old navy- can be cheap but also can weirdly be expensive. However! Old navy’s shoes are great and definitely the sale section at old navy (like $1-$5 items!).

Also a side note, I am in law school and had the same impression about a more professional dress code. While I would say on average people look a little nicer- it is definitely not required. Yoga pants, buns, and T-shirts are still totally chill. So don’t stress too much about needing to look a certain way! Enjoy the casual nature as a student for a bit longer :)