Well, I need to practice my english writting skills, indeed.

Today I thought, that it is a good idea to write notebook entries on the italki.com...
I wrote an e-mail to a person I do not know today; And I am confused on the words "issue" with and "item". It's sad! The e-mail had been sent, and already nothing to do.
I calmed myself, "It's a small point!"
Maybe I need to be more accurate, to proofread my texts with the dictionary or either to do my exercises here, in my notebook. What do you think?

I'm not sure about "Words "issue" with "item". Do you mean to use "and" instead of "with"?

Other than that, a few other mistakes but, you did well! Your English isn't that bad.

Here's the meanings of both words.

Issue: It depends on the context (how it's used). Though the meanings are, to give out; a problem or important topic.

Item: A single thing or object that's undefined.

If you put the words together, such as, "I will issue these items." It would mean, "I am giving out these objects."

Hope this helped! ^-^

Well, I really need to practice my English writing skills, indead.

Today I decided, that it is a good idea to write some notebook entries on the italki.com. Also, I wrote an email to a person I do not know today, and I have confused the word "issue" with "item". How sad! Yet the email had been sent, and there was nothing I could to do. 

I reassured myself, "It's that it was a minor point." (Reported speech works far better here.)

Maybe I need to be more accurate, to and proofread my texts with a dictionary, either to or even do exercises here in my notebook. What do you think?

Well, we say practice makes perfect, and all roads lead to Rome. :) I agree with your ideas. Give it a go!

Well, I need to practice my English writting skills, indead.

Today I thought, that it is good idea to write notebook entries on the italki.com...
I wrote an e-mail to a person I do not know today, and I have confused the word "issue" with "item". It's sad! The e-mail had been sent, and already nothing to do.
I calmed myself, "It's a small point!"
Maybe I need to be more accurate, to proofread my texts with a dictionary, and to do exercises here in my notebook. What do you think?

[Nice work.  Confusing 'issue' with 'item' is a small error, and indicates that your level of English is fairly good.]