Okay, the real trick is to find a method that works for you. People love to shower everyone with advice, especially now that the edtech industry is bubbling with the soaring of Duolingo et al., but from experience only two things are really proven to actually work for everyone:

-Spaced repetition

-Lots of exposure

That's it. The rest is up to you. Some people swear by their specific app, some people religiously study their Assimil handbook, some people will argue that you should never ever learn grammar, some people swear by total immersion, and Nassim Taleb (who speaks like 7+ languages including like Ancient Greek) just reads a lot of books, but ultimately little of it matters insofar as it does one of the above two. There's an overabundance of learning materials out there for you to grab and use, just have your pick and find what's best for you.

Oh, and it goes without saying, but like with all learning, or indeed all cognitively demanding tasks, you have to actually want to learn. Ideally there should be an external motivator that pushes you and from which you can feel rewarded as you learn, this can range from 'watching anime without subtitles' to 'speaking with your SO in their language' but it has to be something.