Several universities record seminars and other talks. Excellent collection can be found on the servers of the IAS, Perimeter Institute, Simons Center, Rutgers, UCSB (KITP). Zoom seminar series: QFT and Geometry, Western hemisphere colloquium on geometry and physics, ResearchSeminars.org
For students wanting to enter the field the following is the required knowledge one needs to get a quick but thorough handle of. QFT at the level of Weinberg I and II. Supersymmetry at the level of P. Argyres notes, Notes of Yuji Tachikawa on N=1 supersymmetry and on N=2 supersymmetry. General relativity at the level of the book of Wald . String theory at the level of J. Polchinski book I and II. All this material can be found in a free book by W. Siegel. (Read the introduction).