I have continued to use the Projects portion of iPhoto because it is MUCH easier to use. I want to migrate these projects to Photos since iPhoto is no longer supported. How?

To migrate your iPhoto projects to Photos open the iPhoto Library with the projects in Photos. Drag the iPhoto Library onto the Photos icon in the Dock.

This will craete a new Photos Library. You cannot merge an iPhoto Library into an existing Photos Library.

But projects do not migrate well from iPhoto to Photos because the templates and formats have changed considerably.

See this support page: How Photos handles content and metadata from iPhoto and Aperture - Apple Support

Some photo books and calendars, made with themes that are no longer supported in Photos, migrate to Albums.

It is better to finish projects you started in iPhoto in iPhoto. The layout of the pages may change.

As long as you can continue to use iPhoto I suggest you complete your projects (if they are books, cards or calendars) and get them ordered with iPhoto before migrating to Photos.