Well, to get likes without having to buy them is nothing easy but with hard work, you can get as many as possible likes in due time. I think first thing first is to ask your friends and families to like your page.
Then, you can try to share the page on the wall of people who have the same interests as whatever the page is about.
You should also try to start interesting discussions just like they do on online discussion forums. And also make interesting and trending articles/stories just like a blog.
Note: if you are trying to use the page in favour of your website, avoid sharing too much of links at the initial stages.