distinct Correlation and Causation of data

i have a lab to find a cause-effect relationship between 2 columns of a data.

First i want to ask: causation is correlation, i mean that causation is subset of correlation. I ask this cause i saw first we need to find what's columns have correlation with the other to find will these have cause-effect relationship. Will 2 columns have no correlation have Causation?

Second, go into real data. i use covid data from link and crawl it day by day. I want to find causation between new cases and new deaths. First i find those correlation, if just use time- line to show , it seem have a causation there

it's the result if i use World data day by day. but when i use scatter plot to go deeper ever country, it show that there no correlation between this 2.

So i tried to use Serious, Critical column to find corr with New Deaths, it'seem like that New Deaths take place later than Serious, Critical. Problem here i don't have more data time-line to demonstrate it.

finally i calculate ratio death/case of every country. but it not show me more info. So i conclude there not enough data to demonstrate have Causation between New Cases and New Deaths . What did i do wrong?