Page Links Default to Homepage

I currently have a website, although not yet complete. I decided partway through building to change to a WordPress layout.

I’ve uploaded all the default files, and the index.php is displaying correctly and I’m able to post. However, I’ve tried to create new pages, but when you click on the Page links they go to my index.html homepage. The same with the Categories link.

This is the WordPress index.php: https://www.lipstickdesignstudio.com/index.php
And the problem are the links in the righthand column.

I’m new to WordPress, so I have no idea how to fix this.

Any advice HUGELY appreciated.