After you’ve found a new language course for self-study, exactly how you use your beginner course depends on what you have chosen.
Try to keep in mind the principle "Use the language in order to learn it". Various lessons will give you an explicit understanding of something that makes you feel like you know it, but you will not be able to use it until you practise.
Understanding the grammar is very different from using it correctly.
The general pattern is to use a beginner course for its explanations and drills, then using input to solidify that knowledge.
If your beginner course already relies on using lots of input, be it through phrases, dialogues, or anything, that is ideal.
Don’t try to memorise your lesson content.
Languages must be acquired, not memorised. Memorisation will make you very good at explaining the language, but very poor at using it.
Don’t try to learn things perfectly first time
Learning happens slowly over time, usually well after you are first introduced to a word or concept.
You don’t need a perfect understanding to learn the next unit, so don’t spend too much time trying to completely learn a concept or word perfectly before you move on.
The very act of moving forward with a loose understanding will help teach you things already covered as you encounter them again.
Study in a way you enjoy
Keeping your motivation up is an important principle, but when it comes to garden-variety desk study, studying languages is not always the most exciting activity.
For that reason, choosing a course and study method that you enjoy is a good idea.
There seems to be a lot of individual difference when it comes to learning method eﬀectiveness. Some methods people tout as effective might not work for you at all.
There is nothing wrong with you, it’s just that the overwhelming factor seems to be the interest and enjoyment of the learner themselves. If you ﬁnd the method you are using is too boring, change it up.