Part 2, please read part 1 first.

Unfortunately, is not easy to find clients willing to pay for this kind of services, especially here in Italy, where authors think that literature is only matter of inspiration.

"This kind" is singular, therefore "service" must be as well. Alternatively you could say "these kinds of services", since proofreading and editing are two different things. However since they are part of the one process, the singular is fine. And it's not just in Italia. I hate being sub-edited which is why my writing is so long and boring!

That's why I don't have any advices for the ones who would like to work in Ppublishing.

1/ "Advice" is a collective noun like "money". Advice may be made up of many pieces of advice, but the advice itself is singular.

2/ "have advice" is OK but it's more common to say "any advice".

3/ It would be more common to say "people who" instead of "the ones" who, but it's not a major issue.

4/ Publishing is only a common noun, and is not capitalised.

The only thing I know is that you have to work hard, as I'm doing for launching my own business. I have an idea for a new digital company that could give me the freedom to finally be location independent. As Which is (or That is) to say, traveling while working. Fingers crossed.

Buona fortuna! Well done.

A job I enjoyed

Part 1

A job I enjoyed

Enjoyed (past tense), or enjoy (present tense)?

"Yet" relates to the job not having given you enough freedom. The best and most correct position for the word "yet" is therefore after doesn't. However another common way of saying this (though it may not be strictly correct) is "doesn't give me enough freedom yet..." However a native s[peaker wouldn't normally say "yet enough" in this sense, because it looks like the word is acting on "enough".

I started to work as books editor in 2011, because I've always been passionate about books.

You edit books (plural), but the job is "book (singular) editor. This is just a convention in English. It's the same as saying "train driver" even though the driver may drive many different trains.

I like reading and writing, but correct and proofread someone else books is like building something.

You have to use either the gerund or infinitive here; that is, either "correcting and proofreading", or "to correct and proofread". There are some general rules about which form you use and when, but in this case either would be acceptable. However these forms are needed to show that this is a process which is not specific to time and tense. You could use "correct and proofread" if you were using it in a specific tense like the future; "I will correct and proofread your next notebook entry, if I have the time" or the past "I did correct and proofread your previous entry ".

You have to seek and extract the real author's voice, made and to make it stand out in a way that even the author himself can't do.

1/ The voice belongs to the author, so you need to use the possessive form; in English that is an apostrophe followed by an s if the noun is singular "one author's voice") or s followed by an apostrophe id it's plural (many authors' voices").

2/ "Made" is the past tense. "To make" is infinitive since you are doing it in past, present and future. (In this case "make" by itself (present tense) would be OK too.)

Furthermore, it is a really immersive job; while you make do it, you don't think about nothing anything but the story.

1/ Your problem here is the verb "fare", which translates as both "to make" and "to do" in English. However you always "do" a job, rather than "making" it.

2/ In English "don't {qualcosa) nothing is a double negative, and it's incorrect grammar. In italiano si usa "non per niente" (literally "not for nothing" but in English that is incorrect (in that sense, anyway); you would say "not for anything". In this case, you don't think about anything.