Unfortunately, I used Word to create my adventure PDF for my first custom adventure, and it looks really crapola. I've been searching for a mac PDF editor that gives me good flexibility and formatting ability, but doesn't cost as much as Acrobat Pro. I used Acrobat for work for a while a couple years ago, but have little experience in the third party PDF editing software world.
What non-Acrobat PDF editors do you use or recommend, if any?
Open Office can save PDFs. I've no clue if it can also load PDFs to edit.
I expect what you want isn't something that can edit PDFs, but a desktop publishing or page layout program. Page layout is the part of desktop publishing where you combine text, images, and other elements onto virtual pages to put together your document. Modern ones output to PDFs so others can view or print what you've created.
You may have used a program like The Print Shop to create cards or posters; that's a simple version of page layout.
Adobe's InDesign is probably the most popular layout program nowadays and is available via subscription. Serif's Affinity Publisher is a cheaper alternative with a permanent license, while Scribus is an open source alternative. There are others as well: (Wikipedia's list of DTP software).
I still use an older version of InDesign (with a permanent license) to create documents, but have been meaning to get a copy of Affinity Publisher to try out.
Hope this helps.