Media, References and Projects all use the same plugin called Testimonials, they are just assigned to different Categories.
To edit: Log into WP, click Testimonials/All Testimonials in the left column. Change the All Categories dropdown to the category you want and click Filter. You can then search for a specific title by name using Search Testimonials. Once you make your edits and have clicked Update, you can click your browser’s back arrow twice to get back to the list without having to go through the whole Category/Search process.
To add: Click Testimonials/Add New. Because of a linking limitation, the titles are “hidden” on the Reference and Media pages. But you still need to add a title and then repeat it in the text box. Insert Media, upload the PDF, link to it to open in a new window, and add your text below. Checkmark Testimonials (or References) in the Category box and then Publish.
The titles for Projects DO appear on the main Projects, so you don’t need to repeat the title in the body. This type of thing is set up in Testimonials/Views.
Click on Envira Gallery in left column. The one you want to add to is called Pics. Click on Edit, you’ll see a box at the top to add more images. You can then drag and drop the images in whatever order you want. Click on the blue pencil icon to edit the images individually, give them Titles (captions), etc. Save Metadata any changes. Arrows at the top of the page to go to the next or previous image.