W3Schools has several Bootstrap 3 templates.
Blog, Portfolio, webpage, Social, Marketing, Marketing2, Analytics, Online Store - https://www.w3schools.com/bootstrap/bootstrap_templates.asp provides a preview of the layout and the code for each
W3Schools has three Bootstrap 3 Themes - these are templates but with more content
Both the Bootstrap 3 templates and themes will require some modification to work with Bootstrap 4, as we saw with the Simple Me example. The Bootstrap 4 Migration Guide at https://getbootstrap.com/docs/4.0/migration/ will be very helpful in doing these modifications.
Dreamweaver CC 2018 has six Bootstrap 4 starter templates.
Revised: April 17, 2018