This is the first attempt of writing my ideas and experiteseences in a written dialry. This is the first attempt of writing my ideas and experiences in a written diary.

This is themy first attempt of writing my ideas and experitencese in a written dialry. This is my first attempt of writing my ideas and experiences in a written diary.

These coming sets of articles doare not just exercise ofs in correct written English or Hhow to Wwrite English perfectly, absolutely not. These coming sets of articles are not just exercises in correct written English or how to write English perfectly, absolutely not.

These is oncoming set of articles do not just exercise of correct written English or How to Write English perfectly, absolutely not. This oncoming set of articles do not just exercise correct written English or How to Write English perfectly, absolutely not.

It isThey are the improvement of the ideas over years and years of struggles. They are the improvement of the ideas over years and years of struggle.

Because you used "these" in your previous sentence, implying there are muliple, this sentence also has to be plural to agree with that.

It is the improvement of the ideas over years and years of struggles. It is the improvement of the ideas over years and years of struggles.

Can also say “years of struggles” but saying “years and years” adds emphasis