Apparently, PDF::API2 is for creating PDFs, it will read them, but a lot of the fields/records will just be binary junk ... which you can replace with various calls
What you're after is CAM::PDF/https://metacpan.org/pod/distribution/CAM-PDF/bin/pdfinfo.pl
$ pdfinfo Test-Results-Cookstove-Performance.pdf
File: Test-Results-Cookstove-Performance.pdf
File Size: 16123625 bytes
Pages: 128
CreationDate: Thu Nov 3 01:02:54 2011
Creator: Adobe Acrobat Pro 9.4.6
ModDate: Thu Jan 5 00:52:01 2012
Producer: Adobe PDF Library 9.9
Trapped: False
Page Size: variable
Optimized: yes
PDF version: 1.7
Security
Passwd: none
Print: yes
Modify: yes
Copy: yes
Add: yes