It's kind of like asking in mid-June how you can get a ripped 6 pack by summer. ;-) Seriously though, there are things you can do to move in the right direction and make "some" improvement. Just don't expect to "seo" your site in 1 month and walk away... although I wish it were that simple! - do thorough keyword research and a competitor analysis to find what search terms you want each of your core pages to rank for. Do you know how many people each month are searching for those or how difficult it may be to rank for that keyword you selected? - take your target keywords and start writing optimized meta tags and content on those pages - update your sitemap.xml file and submit it as well as those newly edited pages to Google for crawling / indexing. That's step 1 out of many steps.