This fall I am starting the 3rd year of my bachelor's degree and I intend to continue my studies with a Master's degree and possibly a PhD. The university I study at is a respected institution in my country but not particularly focused on my area of interest (algebra). I had a first contact, at a summer school, with students from top universities in Europe and I realised I am under prepared for a Master's at one of these universities.

I have a good academic record and did some undergraduate research but there are topics I know nothing about. For example in algebra I had only 2 undergraduate courses (vector spaces, groups and rings- basic definition, properties, isomorphism theorems), no linear algebra aside from the matrix of a linear transformation.

So my question is: what courses are essential to someone who wants to go to graduate school in algebra at a good university and what should I study to bridge the gap?