Hi, Grace:
This community page will walk you through the process of installing PLP:
http://pagelinksplus.com/forums/topic/installation/
As we discussed via chat, you’ll want to make sure these folders are present in your wp-content/plugins directory (vs. in the wp-content/plugins/page-links-single-page-option/ directory):
/auto-pagination/
/page-links-single-page-option/
/pagination-styles/
/scrolling-pagination/
Then, you want to make sure you’ve activated all modules and plugins in the WP admin.
Let us know if you have any other questions, and thanks for your purchase and your interest in PLP.