English is capital essential! Je pense que tu veux dire «capital/essentiel»?

I discovered English 15 years ago, I started to seriously learn efficiently English 4 years ago, and I started to speak and understand things 2 years ago. My level rose from A1 (4 years ago) to B2. What's my secret ?
I worked on 4 importants points every week (reading, speaking, listening and vocabulary) every week. Thanks to 1 book, Assimil, and teachers on Italki :)
I succeeded. Cet implique que vous avez completez vos études. Si vous les continuez, dites «I am succeeding.»
Now it's time to live, my world tour is almost ready to start ... Vos mots semblent très positifs, c'est meilleur d'utiliser la voix active. Donc «I am almost ready to start my world tour.» 

See you soon

English is capital !

I discovered English 15 years ago, I started to learn English efficiently 4 years ago, I started to speak and understand things 2 years ago. My level rose from A1 (4 years ago) to B2. What's my secret?
I worked 4 importants points (reading, speaking, listening and vocabulary) every week. Thanks to 1 book Assimil and teachers on Italki :)
I succeeded.
Now it's time to live, my world tour is almost ready to start ...

See you soon

Great work and an inspiring story! Remember not to put spaces before punctuation when writing in English. 

Hope this helps! 

English is essential/vital/crucial !

I started learning English fifteen years ago, I started to learn  how to use it efficiently four years ago, I started to speak and understand things about two years ago. My level rose from A1 (four years ago) to B2. What's my secret ?
I worked on four importants points (reading, speaking, listening and vocabulary) every week. Thanks to one book Assimil and teachers on Italki :)
I succeeded.

Now it's time to live, I am almost ready to start my world tour. 

See you soon

Advice

1. If the number is below 20 e.g. you should write in print i.e. four years ago not 4 years ago, though not a major error.

2. If the object of the sentence is used twice in one sentence, you can refer to it by the pronoun the second time. e.g. first time English second time it.

3. With regards to the world tour, as you are the person doing the action it is best to say " I am about to start my world tour.

Good Work Romain I hope I can follow your advice and do the same with French. Where are you going?