If by ‘Like’ button you are talking about the button at the top of your site in the admin bar, then you want JetPack. It’s got that plus a whole lot of other cool things to make your blog more ‘wordpress.com’ like.
Hope this helps, if it’s not what you were after post back and I’ll see if I can help further.
Hello, Trisha. Thanks for replying 🙂 I’ve actually downloaded JetPack, and it’s activated. No ‘Like’ button though. Oh and by ‘like’ button, I meant the one where you would see at the end of each post/page.
Hope to hear from you soon!