Moving from wordpress.com – Need help with infinite scroll

Hi,

I am in the process of moving my small personal site from wordpress.com to a self-hosted server, and I am now trying to get the installation to do everything that I had on my old site. Currently, I am struggling a bit with the “infinite scroll” feature. I am aware that there are several plugins for that, but I couldn’t get any of them to do what I wanted:

Ajax Load More
Simply activating the plugin didn’t do anything. From the documentation I take it that I should use the short-code builder that creates snippets like this:

[ajax_load_more post_type="post" posts_per_page="6"]

The only problem is that I don’t know where to paste the code. I tried putting it in functions.php in a number of ways but nothing worked.

WP Infinite Scrolling
Again, just activating didn’t do the trick for me. Going through the settings I would assume that I’d have to adjust the “post container selector”, “post selector”, “pagination selector” and so on, but I have no idea how.

Infinte scroll
This plugin actually works, in the sense that it loads new content when I get to the bottom of the page, unfortunately it does so in a rather messy way: I have three columns in my theme, but the plugin only fills two, it sometimes leaves large blank spaces between the posts and it works a bit laggy in general. Nothing compared to the smooth flow I had on my wordpress.com site, where the boxes seemed to fly in from the side, stacking up as you watched, into the same layout as on the original page.

As a general info: I am using the Visual theme, I created a child theme so that I could easily make adjustments that don’t get lost on updates. However, the only adjustment I made so far was to enforce word-break:normal in the style.css and enqueue the parent style in the functions.php. Sorry if my terminology is a bit confused, I am still quite a beginner at wordpress x)