Most of the information on this page is taken from the website of Christoph Kronenberg who I thank you for putting together such an useful list of resources.
Data Science
Econometrics
Free text books on econometric methods with focus on causal inference
Free video resources on econometric methods with a causal inference focus
Free coding resources
Mostly Harmless Econometricsin Stata, R, Python and Julia.
Other useful links
Academic citizenship
Academic writing