Thank you so much! I appreciate your comment! :)
I recently found out about the EastWest ComposerCloud+ Library and it's mainly what I've used for these pieces. It's a subscription-based collection of insanely good libraries with the most variety I've seen so far. Especially for students, the price is well worth it ($10/month with a student subscription). Most of the libraries take up a looot of disk space tho so keep that in mind.
Other libraries I've used in the past are Spitfire's BBC Orchestra (there is also a very decent free version) and LABS, which is completely free.