If you haven't previously had MS Office installed on your computer, you can download a 60 day trial of the MS Office suite
(note that of the compilations listed on that page, only "professional" has Publisher). That trial will hopefully help you to complete your current issue within reasonable time. Not sure how it works if you've had a previous MSO version on your system, but if you had 2007 or 2010 trial preinstalled when you got it, I guess the trial will display an "immediate expire". Workarounds may exist, but that's beyond the scope of this forum, and also beyond my capacity at the moment.
While your trial is still functional, consider converting all your archived publisher material to PDF/A or some other future proof storage format.
When you get your head above water again, consider changing to other software. I have no deeper knowledge of DTP software, but as far as I have tried Scribus it has the functions I need, and it is reasonably user friendly. You don't get all the help and guidance that the Publisher wizards provide, but once you have your templates properly set up, it's an efficient tool.
If you still want to use OOo, I'd use Writer for publications, and perhaps Draw for posters and single sheet brochures.
Draw is page oriented, so in some senses it's more like a proper DTP application. However, it lacks some important functions which are useful for larger documents.
With Writer, use frames for all
your content. Note that Writer is oriented towards text flow, so if you change size of content/objects, other objects in your file may jump around quite a bit as Writer tries to "reflow".
Note also that text wrap is only functional within each frame. If you have a graphic that goes outside the anchoring frame, you need to make extra measures to have outside text (text in other frames) wrap properly.
Column formatting within a frame is usually better than linking frames side by side when you need to make columns.
Apache OO 3.4.1/4.1.2, on Ms Windows 7/10 and Mac OS-X. LibreOffice 18.104.22.168 on Mepis Antix MX