First and foremost, I speak Croatian pretty well, which is a second language for me. I am working on French at the moment, and that is what I will be focused on for the next 1.5 years. After that, I will go on to learn German. But, a lot of people speak English in the European Union.

I also use nifty and unique tools like this, which helps me learn languages in my sleep (I use it for engineering coursework too!): https://github.com/Frederik-D-Weber/cosleep

I also wrote a script that creates 10,000 Anki flashcards: with the English (10,000 most commonly used words in English) and the corresponding Foreign word, IPA pronunciation (English and Foreign word), Text-to-Speech audio (for both the English and Foreign word), and a GIF image corresponding to each flashcard.

With respect to becoming conversational, this is the best tool: https://ai.glossika.com/

This is a good place to figure out good learning methods: https://forum.language-learners.org/

I should point out that you never need to go abroad to learn a foreign language. You can just find the cheapest person on italki who is a native speaker of your target language, and have a session with them, where you only speak words in the target language. That is the best way to learn.

But, this is the ultimate guide for learning a language. Basically, from there, it is a matter of finding inputs/outputs (materials to learn from) to work with in the foreign language: https://www.wgtn.ac.nz/lals/resources/paul-nations-resources...