Issue 1:
If you don't see the Testimonials or Portfolio sections in your dashboard
Please make sure you've activated the Unplug Jetpack plugin in Dashboard > Appearance > Install plugins
Issue 2:
If the Unplug Jetpack plugin is activated and you still don't see the Portfolio and Testimonials sections, please check if the Custom Content Types section in Jetpack > Settings is enabled:
Next click to toggle the Custom Content Types section and enable the Portfolio Projects and Testimonials posts.