Hello,
1) Please watch this video – https://xstore.helpscoutdocs.com/article/93-variation-swatches
Here are settings of variation swatches from our default demo – http://prntscr.com/p5yws4
2) https://xstore.helpscoutdocs.com/article/65-woocommerce-infinite-scroll-and-ajax-pagination-settings
3) https://prnt.sc/p5yx1r
Let us know if you need any further assistance.
Regards