I've checked my Downloads folder and I see that the installation file for Serif PagePlus SE is still there. So I've uploaded it to here for you:
https://c.gmx.co.uk/Buenchico2@gmx.co.uk/DmfOVVt9RdeA6bXrpKqoog
(Simply click on the file name to download it. I'm confident that my PC is virus-free, and that the file-hosting service I've used is secure, but good practice still dictates that you should right-click on it and run a virus scan before proceeding any further).
Once you've downloaded the file (and scanned it for possible virus infections) you simply need to double-click on it to run it. However you'll find that the program then asks you for an activation key. So I've just logged into my Serif account to find out the key which was allocated to it. It's
PLX7U-SER01-11922-28148-12864
That should be all you need.
(I'd normally deprecate the sharing of software and product keys via AB but that program was always a freebie anyway, so it doesn't seem unreasonable to share it with others here).
PS: While PagePlus is a great program for ease of use, if you're ever tempted to try a (free) 'professional' program, equivalent to the mighty QuarkXPress used my many major publishers, look no further than Scribus:
https://www.scribus.net/