[Question] Courses relevant to geostatistics?

Hi! I’m a PhD student in political geography with strong interests in geostatistics. However, neither my own nor neighboring universities explicitly offer any such courses. I have a strong empirical background—probability theory and statistical inference, causal inference, machine learning, etc., as well as various programming courses. Might anyone have an idea of what sort of courses might be helpful for more strongly learning geostatistics without any explicit such offerings? I figured perhaps stochastic and time series statistics and network theory would be helpful, but I’d appreciate any more insight. Thanks!