Thank you very much, some help and tips would be super appreciated! What would you recommend doing?
These are the topics we did:
Discrete Math
Combinatorics, Group Theory (Cycles, cycle decomposition, parity, order, subgroups, cyclic groups, homomorphisms, Generators and relations, permutations of S~n~, generators), Number Theory (Bezout's Identity, Euclidean Algorithm, Euler's Totien function ϕ, Euler–Fermat theorem, congruences etc.), Modular Inverses and Equations, and the ones that tricked me the most, Abstract Algebra. I think these should be all.
Linear Algebra
Complex Numbers (with Polar coordinates and roots), Matrices (Matrix operations, trace and determinant, inverse, special matrices, ranks), Vector Spaces (subspaces, linear independence, coordinate vectors and change of basis), Linear Transformations (Eigenvalues and eigenvectors, diagonalization, and some other stuff), Inner Product Spaces (I literally know almost nothing about this)

Yeah, these are the things we did in our first semester, so I wasn't the only one thinking the curriculum is kinda nuts!
Thank you a lot for the explanations and the advices! I'll make sure to follow them. One of these days I might try using Matrix. Thanks again for the detailed response and the patience!!