It appears that the issue is with human friendly urls not being properly resolved. As I recall, there were some issues with that capability back in DotNetNuke 4.09.xx and early 5.xx days. Why it worked on the prior host and not after the migration I can't figure out. It could be due to a change in ASP.Net or IIS version. I would suggest asking the hosting provider for that information.
One other question (that may require asking your hosting provider as well): was the install on the old server and is the install migrated to the new hosting provider both using the standard web server port 80 has that changed?
Although using human friendly urls have some advantages, let's try turning them off and see what happens. In the site's web.config file find the following section (about 2/3 of the way down from the top as I recall):
<friendlyUrl defaultProvider="DNNFriendlyUrl">
<providers>
<clear />
<add name="DNNFriendlyUrl" type="DotNetNuke.Services.Url.FriendlyUrl.DNNFriendlyUrlProvider, DotNetNuke.HttpModules" includePageName="true" regexMatch="[^a-zA-Z0-9 _-]" urlFormat="humanfriendly" />
</providers>
</friendlyUrl>
Note in particular the attribute/value that I have highlighted in yellow. Remove the entire attribute and its value then re-save web.config and re-upload it to the web server.
Let me know if this allows you to regain access to pages other than the home page. The disadvantage of doing this is that search engines have indexed the old site using the human friendly urls and users navigating to old serch engine links will receive 404 page not found errors. For that reason, it will be best to then determine why human friendly urls are not working on the new host, correct that issue, then add the attribute/value back into web.config to restore human friendly urls.