Faineance, friction and computer…

When I go to the library, I always like to borrowing the latest and most expensive books .

But reading books of different topic of books at the same time do haveis a problem.

You may learn many different knowledge but only from one book.

Do you mean you can really only learn from one book even though you are really several at one time ?

I decide within a month Ito read only read one topic of booksne month.

For example soon is March.

Better combine this sentence with the next.

So, in March IFor example, I will only reading books about “Bitcoin” in March.

At the end of the month I will count how many books I have read.

one month one taskThe theme of the month/ The topic of the month

One month one topic

I would delete this, as you said this in the title.

Faineance, friction and computer…s are two subjects I like. I also like reading fiction.

Finance and computers are subjects. Fiction is a genre. It would be better to use to separate sentences. Friction is a word in English, but if that is what you mean, you should give some more information.

When I go to the library, I always like to borrow the latest and most expensive books.

"go" normally needs a directional preposition like "in the" or "to the" (depending on the sentence). "The latest" is a superlative. It needs a noun (books). To make the superlative form for "expensive", we need "most".

But, reading books on different topic of books at the same time do have ais problematic.

a book on a topic; something is problematic. Or, construct the sentence differently. "I have a problem reading books on different topics at the same time." or "I find it difficult to read books...."

You maycan learn many different knowledge but only from onthings from a single book.

I'm not exactly sure what you intend to say with this sentence. This is what I think you mean. Perhaps you mean that a person can only learn from one book at a time.

So, I have changed my picking style.

Present perfect is a better tense.

I have decide within a month Id that I will only read books on one topic of bookswithin a given month.

For example, it will soon isbe March.

So, iIn March, I will only reading books about “Bitcoin”.

At the end of month, I will count how many books I have read.

We separate introductory clauses with a comma.