People spend years studying epidemiology. No one can write a comment here that will teach you how to do it properly.

But I'll try to help. You're looking at a graph of confirmed cases, in other words, positive test results.

That may be due to an increase in the number of infected people; or because the number of tests being performed is increasing, and therefore the percentage of infected people reported as confirmed cases is increasing; or because some positive test results (even with confirmation) are false positives. And there may be other causes that I don't know, because I'm not an epidemiologist either, just a statistics grad student.

Figuring out the the contribution of each cause is a job for the professionals.