15-20 days are not enough to get rank in serp. It takes minimum 3 months to get rank and traffic from SERP. Try to measure your activities and backlinks. There are several ways which can help you to get the rank.
1. Do the interlinking blogs and websites.
2. Create the proper meta tags using targeted keywords.
3. Put the keywords in your url.
4. Generate the links from Guest Post, Web 2.0, Articles, Profile Creation, Microblogging etc.
5. Use Social Media.