You typed a search term in the search box and now you have a bunch of results and they don't seem to be what you want.
Check your filters. The filters are located on the left side. The ones that you want are under the heading "Types".
Change the filters for type to match what you want in your results.
If you want lots of images and pages from books select "Images" and de-select everything else.
If you want to see only the subcollections select "Folders" and Collections/Subcollections and de-select everything else.
If you want videos select "videos" and de-select everything else.
If you want books, documents and PDFs select "Folders" and de-select "Collections/Subcollections" and select "Other"
If you only want PDFs then select "Other" and and de-select everything else.
This should adjust the number of results that you see.
Step 3. Your results
If your results don't seem to make sense after you've filtered them, check the view sort and set the sort to "Relevancy". "Date Created" is the date that the file was loaded in the system. Not the date that the photo was taken. "Filename" will sort the files into collections by file prefix.
Images with a stack of paper icon on top of them are folders. If you click on a folder you will see more things. It may be images, audio, video, text.
If you find that a folder is completely out of order, find the view/sort button and sort the folder by filename ascending.