That is a HUGE question.

You need to make sure your site is properly optimised, things like titles are correct for the keywords you are targeting. you need to ensure your keywords are used on the apges you are targeting. You need to ensure you have backlinks to the site, using a slay of different keywords that you are targeting etc.
LOTS of things work on getting you rankings. I have written a 50 page book on it and that still doesn't cover everything

I suggest you look at things one step at a time, rather than as a whole.