There are many many different people with different advice. Just do a search in any engine, eliminate the AI-slop and use what of the rest seems like you can do.

The most important factor is putting in your hours of study. You can never learn a language if you spend all your time learning how to learn a language. You will never learn a language if you good at one basic and never study anything else (which is what most programs, including doulingo will get you, so you need to try several different study methods)