Learning a Language.

I have been studying English for years. When I first started I didn't know how important is was, but now I know that it is useful in school, employment, and travel. I enjoy studying English, but I do not have anyone to practice speaking with, so I practice by talking to myself. 

Learning a language.

I have been learning English for a few years some years ago, but when I started I didn't know the importance it had (1).  So, a year ago I realised (2) that English is really important for everything: school, work, travel, etc. job, travels...  Something unexpected is that after I started to like English, it became easier to learn. But, after I liked English and it was going easier to learn, a funny experience. (3) Unfortunately I don't have haven't opportunities to practice my speaking, talking with other people, so, I must to practice on my own.

A few extra notes:

(1) This is not wrong as it is, but I think it sounds a little more natural as "... didn't know how important it is"

(2) Realised is the spelling used in England. It is spelled realized, with a z, in the US.

(3) I'm not 100% sure what exactly you were trying to say here, so I guessed. If my guess is not what you meant, feel free to write your original thought in Spanish, and I can probably help you translate it.