I think that learning and appropriation ofcquiring a new language is something difficult, especially if you can't be exposed daily to that language.

Or: "the learning and acquisition of." "Appropriation" is not appropriate here, since it refers to taking something that belongs to someone else, in a negative sense.

I have the purposegoal of improving my abilities within English, but this is challenging for me.

It only makes sense to say that something or someone has a certain purpose if you're discussing what something is for. For example: "This balm has the purpose of healing burns."
"Abilities in English" unless you mean to say that you're improving some other ability (like communicating with others, maybe) by learning English.

So, I'll start with English conversation classes, and I hope to be better atin this topicarea.

"Topic" is more specific, and it tends to involve some set of specific ideas or competencies as well.

I think my problem is that I can´'t stop trying to translate from my own language (Spanish) to English.

"My language" is grammatical, but "my own language" or "my native language" are better since it makes the contrast between the two things clearer.