Being a first year Master's student, I wish to pursue my research on the aforementioned, but the abundance of resources ended up confusing me as to where to start. Suggestions are appreciated.
You should not forget, that ads Correspondence has not succeeded in extending the correspondence idea from ads to more realistic space-time manifolds and ads has absolutely nothing to do with reality.
might be a good starting point. Another useful paper, that was a precursor to the AdS/CFT correspondence is
Article Microscopic derivation of the Bekenstein-Hawking entropy for...
The journey however actually starts from general relativity, where it's understood that the conserved charges are defined only on the boundary of any spacetime, provided it's flat, since only under such circumstances can these be globally defined (since global conservation laws can only be defined on flat spacetime). The reason AdS (anti-de Sitter) spacetime is particularly useful is because it can be shown that any extremal black hole spacetime has AdS as a factor of its near horizon geometry. It doesn't have anything to do with cosmology directly.