I am using a pull to refresh on my page. But the page also loads "OnInit". How do I let the user know that the current information is old when it is initially loaded? Should I trigger the pull to refresh animation?
The information you load onInit shouldn't be old, it should be the latest one (think Facebook). I'm not sure why you're not doing it by that, but that should be the default.
As for new content (I'm not sure because you mention "refresh animation") you could have a toast or any other kind of alert dialog that let users know there's new content. This site is a good example, if you go to the main page and wait for a bit, you'll see a small alert on top of all posts letting you know there are new questions with activity