Infinite scroll usually requires some kind of Javascript library to load more results via Ajax. The basic idea is this:
- User arrives at your page, you show, say, 5 posts per page
- They scroll past a certain offset and you use JavaScript to trigger an Ajax request
- Your request passes the requested paged, the endpoint receives the request, and returns just the HTML of the posts you want.
- You handle the Ajax response and insert the HTML in to the page
Here is a good writeup from Smashing Magazine on how to determine if infinite scrolling, pagination, or “Load More” is best for you.
Some other tips:
- You probably don’t want to load all posts at once – this may not be an issue now, or for a long time, but eventually this will come back to bite you
- There are plenty of plugins and tutorials for doing this, you just need a good understanding of how it works