<em>Here are some different ways to write this.</em>

The software will be useful

Yesterday, a bussiness partner wanted to sell his company to me.
I'm interest in his company but I don't have no enough money.

Today, I paid 10,000 yuan for new software.
The software has a website and a mobile website, with the main funtion of boardcasting product information.
That's will let more customers find me on the internet.
I hope the software is really useful.

The software will be useful

Yesterday, a bussiness partner wanted sell his company to me.
I'm interested in his company, but I do not have no enough money.

Today, I paid 10,000 yuan for a software.
The software has a website and a mobile website, and the main function is to broadcast product information.
That's will let more customers find me on the internet.
I hope the software will be really useful.

A very good start!  It was easy to understand what you were trying to say, there were just a few errors in your tenses and spelling. Keep it up! :)