3/26: I created the Wordpress website on a live server. I downloaded a copy to my XAMPP server. I exported the database and created a local one. I modified the wp-config.php file to connect to it. That all works.
However, I am not able to use any of the links in the navbar and otherwise to open any of the pages and posts. All those hyperlinks have absolute addresses that use the domain name of the live server.
I can add the directory path and go to "/index.php" under localhost but all the other paths are open-ended with no file name and they do not work.
If I do not use "index.php" and just have a "/" it will not go to the homepage. For the homepage, if I leave out the "index.php" file name, it will have the header and navbar and say "Oops! That page can’t be found."
If I use open-ended links to anything else, it will say "Error establishing a database connection."
3/27: Thank you all very much for your responses! I have a plugin installed that I have not used yet called "Velvet Blues Update URLs." I will give that a try. I also have "All-in-One WP Migration" and "Duplicator," but the website is over 600mb in size so the free versions of those will not work.