You could start by going through some Accounting or Finance videos from edu sites like Khan Academy, and also spend some time looking at the financials for public companies on a site like Yahoo Finance. Annual statements are also available on EDGAR (
https://www.sec.gov/edgar/searchedgar/companysearch) rather than, e.g., Yahoo Finance, but maybe a bit harder to parse even though its closer to source data.
I think you only need some basics to learn how to look at a financial statement and understand information like whether or not the company is profitable, or roughly how long the company can survive if things continue the way they are, or get better, or get worse. If you want to be able to really understand and assess a business and its financial health based on these statements, I'm not sure you can just learn that. I certainly don't have the confidence that I can do that yet. My feeling is that I'd probably have to work in the industry in some capacity where I am looking at this information daily, across dozens or hundreds of companies.
At best, I can pick up on anomalies that can later be explained (e.g., I saw there was a large amount of cash added to GitLab in the past year, and later it was clear that this was largely because of their IPO, which seems obvious but nobody told me there was an IPO before reading the statements (granted, the existence of the statements tend to imply this is a publicly-traded company)). That gives me some confidence that I know what I am reading, but I haven't done much outside of Khan Academy videos and taking a university-level accounting 101 course where I learned about the accounting equation, the accounting cycle, and how to write financial statements based on the financial events for a business.