Help! What specific knowledge should I contact first if I want to learn quantum mechanics?

Mathematical basis: calculus, differential equations, mathematical field theory, determinant, matrix, linear algebra, permutation and combination, probability theory.

Physical basis: general physics, atomic physics, theoretical mechanics, statistical mechanics.

The mathematics part is university mathematics books, such as three advanced mathematics books compiled by Sichuan Institute of Physics and so on.

For the physics part, I recommend three Feynman lectures on physics and the new concept physics series edited by Zhao Kaihua, or just college physics books.

Add a few more points:

1) the mathematics part will also use the series solution of partial differential equations, functional analysis, complex variable function and so on in mathematical physics methods; It seems that there is no special math book for Yi Algebra, that is, you study synchronously when you study quantum mechanics. Group theory is also very important, but it is only needed at a fairly high level, so there is no need to learn it now.

2) In physics, we should learn the special theory of relativity. Higher-order quantum mechanics is relativistic, such as the famous Dirac equation.

3) Personally, I suggest you start teaching yourself quantum mechanics at once. No one will learn it once or twice, and it usually takes several times to get started. Therefore, it doesn't matter much if you start learning for the first time now, just be mentally prepared-you will encounter many difficulties, and many places have to be put aside for the time being, and then learn thoroughly after N times. I think it is appropriate to make up those foundations between studying quantum mechanics many times.