Welcome to Sitepoint @Revanth_Kumar;
I think you should ask yourself, "How did we get those first four customers?" Whatever you did there, you should repeat.
Additionally, as with ANY BUSINESS you need to
- Determine who are your potential customers
- Go to where that type of people congregate
- Share business cards and your story*
Joining and attending meetings of the local Chamber of Commerce is a great way to locate small to medium businesses who probably need Website services.
Offering to do FREE work for community and charity causes in the neighborhood can generate a lot of attention to your abilities.
*Your story should be the "elevator speech" Think about what you have to offer, that your ideal customer simply could not live without, and describe it very clearly and succinctly in just a few sentences (short enough to relate during a ride in the elevator with a stranger)