The most important meta tags are “description” and “keywords” for the seo. There are some plugins which are doing this but you can also do this manually.
Note: This way is recommended for single page themes. For others I recommend you to use a seo plugin like the following;
1) Go to Appearance->Editor
2) Open header.php file
3) Add the following codes right after “head” tag
<meta name="description" content="Your description here"> <meta name="keywords" content="keyword1,keyword2,keyword3....">
4) Don’t forget to add your own description and keywords…
Important: Google doesn’t notices these changes immediately. It may take 1-2 week…