Another Transitions in iMovie (10.0.7 latest)

I just bought my first iMac (brand new) and see transitions in TEMPLATED movies that are not available in 'from scratch" ones.

I previously was in Windoze-land using Corel's video program with all sorts of transitions, where this iMac comes with very few.

Should I assume that industry-standard plug-ins will not work? How do I add some more (like Apple iMovie Plug-in Pack) and to what folder?

Same for titles. So far, the program is great, but titles and transitions seem too few and not addable.

Is this right?

Thanks for helping the newbie!