How to rank on a spesfic keyword

Hello,

I was wondering about this topic since i started learning SEO . How do I target a specific keyword to rank on using backlinks . For example if my niche is Battlefield 4 Beta key . When someone searches for Battlefield 4 Beta Key he will find my website , but how can i rank it on the keyword "Battlefield 4" only ? and how can i rank my site on the keyword "Battlefield" or "Battlefield 3" ? I hope you understand what is my question
P.S : I'm ranking YouTube video on Google

Thanks in advance

Just start adding content with LSI and start building the link with diversification..