UKC

If a hired pro using Illustrator can achieve a 10/10 result, I'm looking for something relatively simple and intuitive on which I'm likely able to achieve ~6/10 doing it myself (good enough for this project).  Can be online or downloadable (torrenting fine too), ideally works on linux though windows 10 feasible.  Essentially just need to layout photos, text, images, etc. on A5 sheets and be able to export as pdf or even jpeg.  (vector formats prob overkill)

Thanks a lot

Have a look at Figma, its free and pretty much the same thing. Although its based around web design, you can export at a higher res for print, but it wont support CMYK etc.. 

If you're going super simple, Powerpoint has all those features.

Now we're talking, thanks a lot.  Libre office - Impress (equiv to powerpoint) is perfect.

If you want something approaching the power of Adobe Illustrator but for £30-£60 depending on available deals, look at Affinity Designer. Probably OTT for what you are after though.

On Linux Pinta is very simple to use.  Gimp is harder, but the gold standard in terms of capabilities.  Both free.

For DTP type stuff you want scribus

For ppt then libreoffice is equivalently as shit as powerpoint

For illustrations / photos etc gimp is what you want

For drawing some like inkscape (but xfig is better if of a certain vintage)

3d Blender

Inkscape? Vector based like illustrator so not ideal if you want pictures in the mix. What you really want is an equivalent to inDesign. Publisher is better than PowerPoint for this.

That's not really the domain of a graphics package; more like simple page layout tool, unless you hope to create pretty 'images' in the tool, as opposed to simple line drawings.

LibreOffice Draw would do all that.

It's Arty-Farty but I love Krita (it's free). Really lovely brushes.

Sounds like you need Scribus

The 30 day free trial of Canva Pro would be a good shout. Has a ton of premade templates and elements to add to your design and is dead simple.