Pages show up in Dashboard but not on public site

My issue is that on the Dashboard side, all posts and pages seem to look correct.. I can add a new post, and it shows up in assigned location. But the only page that functions is the home page.

https://www.cit-asl.org/new/

Background to issue
My WordPress site started sending spam through a contact form to me last night… I woke up to thousands of messages. (I am not sure if spam was going through any other direction. I am in communication with my web host about that.) To shut down the spam, I installed a new version of WordPress through cPanel File Manager – and moved the old version.

I then copied config file and files from wp-content>upload over to the new installation. This meant that the home page opens up and looks like it is working.

I also copied over Theme and plugins, though I have turned all the plugins off to check if that is the issue.

Everything looks good on the dashboard side.

But when I try to go to any actual post or page, I get 400 Error message that the page is not found on this server.

In the dashboard, all the pages are there full of content. Is there something else I need to copy over for the site to be able to find the pages on the public side?

Thanks for any insight someone might have. If there is a codex that shows what I need to do for a fresh manual install connected to an old database, I couldn’t find that.