From the sixth grade we start learning English, and we often must study it until university, even if the field of our studies has nothing to do with it. Only having to work in English in middle school, high school, college or other training can be quite constraining and demotivating.
Only knowing how to speak English has become essential, as it opens more and more doors for you (travel and professional career).
For this reason, I recommend that instead of studying in your area, you spend some time in an English-speaking country. Not only would you consolidate your foundations by using them, but you would also learn new words. Communications, reading signs, documents... you will benefit on site from the best tools to progress (provided of course to use them!).
A stay of a few weeks will not allow you to become bilingual but to familiarize yourself with English and gain more self-confidence when you express yourself.
To master a language, there is no better way than total immersion. This method is radical because you will progress at high speed. You will discuss, think and even dream in this language! A strange and rewarding feeling, which I invite you to discover.
As for speaking as well as your mother tongue, it is recommended to stay in the country for a few years (your progress will obviously depend on your activities). But to make it quicker, I strongly recommend the language course (with Prolinguis no example); not only will you speak, but you will also study the language more thoroughly, as you did for your mother tongue at school.
In addition to this, you can benefit from practical information and support to learn how to manage your daily life in the foreign country (accommodation, work, activities...).