I need a technique about how can I get a site at the first page of Google?

First let me echo, while the 1st page is good.. only the top 3 pay on a consistent basis and you will see a very clear different from positions 1, 2 and 3. An example for a page I am working on at the moment works like this:
Position
3: Earns about 1 to 2 dollars a day
2: Earns about 4 to 6 dollars a day
1: Earns about 15 dollars or better a day

Now one big factor is the number of searches and potential traffic, this is based on 5400 a month. I would make sure you know their policy concerning the need for them to remove links and get it in writing now because I have noticed a few threads recently regarding this and some clients having to pay to get the work done. Just know what you are getting into up front especially with Google updates coming down the road.

 

The best technique for you is SEO. You better try Social media optimization as well.