People Search

First of all, you need to know how the Internet works and not expect that everything is there.

The Internet is not an official structured database, but a large group of sites created by enthusiasts or businesses for their own purposes.
There are official sites with databases, but they are closed and search engines will not give anything out.
There were sites where the base was posted from various official sources - such as the traffic police, etc., but they were quickly closed, because it was a violation of the legislation on protecting personal life.
Therefore, on the Internet you can find basically only the information that the person himself posted about himself, can at registration in social networks or in some other Internet service. Again, registration in decent online stores and official services will be hidden.

Also, keep in mind that a person may incorrectly indicate a date of birth (I usually write the date formally, I do not like receiving spam on my birthday, let it be less than congratulations, but only from real friends and family, and not from all Who found the verse on the Internet).
Someone just hides the year.
Not all indicate the active phone number, so that it does not fall into the hands of collectors.

How to find a person?

Through the search engine, but I can not be found there because my namesake is Mayor Peter.
Be sure to search in Odnoclassniki.ru or in similar services.
Order a detective agency, of which there are many, including on the Internet, but we can not recommend, therefore we will not.
Through a special search service.