Custom SEO URLs

[tinyhands]

Hello,
I'm trying to figure out how this can be done. I understand that with SEO friendly URLs selected in Prestashop I can get my categories looking like this:
http://example.com/1-firstcategory
http://example.com/2-secondcategory

And for the CMS this is how it appears:
http://example.com/content/1-aboutus

And for product pages:
http://example.com/firstcategory/1-first-product-name.html'>http://example.com/firstcategory/1-first-product-name.html


Is there a module or code change to help me create URLs like these instead? My previous website had links that looked like the following, so I would like to maintain the URL structure like so:
http://example.com/firstcategory
http://example.com/aboutus
http://example.com/firstcategory/first-product-name (without .html)

Preferably looking for a fix that allows my pages to stay intact and not "disappear" haha
Thanks!