To achieve SEO rankings, first you need a strong website which has all on page factors implemented and tested and having a unique, fresh and relevant content. All links should be working and the internal linking structure should be strong. After having SEO friendly website, go for promoting your site.
With unique content, you can do the activities like social media marketing, Blogs, Guest posts, blog comments, article marketing etc.
If all will go right then you can achieve Good results with short time.