I wish to have free sample[s] of how to write an introduction letter of my company.

Hi, UDEME ANI!

This sort of information is available in many places on the Internet. Please click on the following search.

How to write a company introduction letter. - Google Search

If you would like to post a draft of your letter here, I'm sure that there would be those of us who would be willing to advise you as to how you might make improvements to it.

Thanks!

Management Help Library can help you write your sales letter. It alos provides information for other business aspects. I use the Sales Proposals section a lot.