there was a study saying that there is not "the" best way of learning, but it is best to combine multiple ways, like with an app, by book, listening to audio only (i listened to radio stations via internet and got some exercise for free), a bit of talking, visiting a country that only speaks that language and so on. trying everything a bit in parallel.

that is because of our brain learns better when given more different types of "connections" to learn.

i started with duolingo (website only, not the app and only the free parts) 4 years ago and now i speak quite fluently. but i also partly read a book about grammatics, visited a spanish speaking country (more than once), viewed movies with only subtitle in my language and did lots of phone calls in spanish only.

my advice is:

look at free apps, whatever pleases you, take chances, listen to the sound (movies, radio), try to speak, and read easy books or go through exercise books.

duolingo is good to keep on going while not really motivated as the shortest thing that counts are really only minutes and one can choose to do something that is already easy. this way at least continuation is kept even if pace is down for a while. and it is much easier to go on with pace when not having really stopped.