The best way to learn any languge not only English is:

1. Follow a well desinged plan of your choice.

2. Get the materials you need.

3. Listen to audio/video materials of the subjects you are interested in even if you don't understand a single word!, you can add subtitles as well in my case I watched animes, movies, tv shows, documentaries, read as well as much as you can. Don't try to get 100% of the meaning of what you are hearing!

4. Use your language as a tool of communication fom the first day!

5. Think in the language you want to learn, talk to yourself in your head, use the language you want to learn to express your thoughts.

6. If your not happy, relaxed, or not in good mood quit learing and get a rest.

You know why I think this steps are true? because they worked for me. :) and good luck!

I can say, developing listening & speaking skills by listening to songs ( memorise lyrics & understand them), watch movies & try to talk to others.
Developing writing skills & start with short passages( talking about yourself, your day) get help from people who can correct your passages.
Ps: learn each day new words & try to use them in your daily life ( Don't be shy).

Probably to go to school for it, English can be a confusing language with all it's different rules.

Step one I think would be to learn the alphabet, that's usually how beginners and english children are taught.

Goodluck :)

practice makes perfect.

Practicing !!