Abstract algebra

These are a fantastic set of notes https://homepages.warwick.ac.uk/~maseap/teaching/aa/aanotes.pdf

Darij Grinberg’s "Notes on the combinatorial fundamentals of algebra" on the interweb at (http://www.cip.ifi.lmu.de/~grinberg/primes2015/sols.pdf)

Seth Warner’s \sayModern Algebra (it’s an amazing book).