It is not easy to learn a language. It is a big undertaking. But if you need to or want to, it can be done. Just consider a goal and work towards that!
In this article they talk about how to learn English.
Part 1 - Improve your spoken English
1. Speak English a little every day
2. Work on your pronunciation
3. Expand your vocabulary & idiomatic phrases
4. Attend an English class or a discussion group
5. Carry a dictionary
Part 2 - Improving your writing, reading and listening skills
1. Listen to English radio or podcasts
2. Watch English movies and TV shows
3. Read an English book, newspaper or magazine
4. Keep a diary
5. Find an English speaking pen pal (LINE pal)
Part 3 - Committing to your new language
1. Stay motivated
2. Practice every day
3. Train yourself to think in English
4. Make friends with English speakers
5. Don't be afraid to make mistakes