I don't have Photoshop or Illustrator - if I were to purchase one, which one would you recommend?
Both are completely different apps intended for different uses which makes that a fairly tricky question to answer, but I’ll include a bunch of info below which will hopefully help you with your decision.
The main difference between the two Adobe apps is Photoshop is a pixel-based app (raster files) while Illustrator works using vectors.
Vector means you can scale your work up or down without losing quality as it doesn’t rely on resolution. While raster based files have limitations in how much you can scale-up before losing quality and becoming pixelated as these files are resolution dependant.
Both have pros and cons, but if you are very new to design apps I would say Adobe Photoshop is easier to learn and quicker to grasp. However, if you are planning to pursue design more seriously, I would recommend Adobe Illustrator which has far more flexibility and is easier to create designs and layouts compared to Adobe Photoshop (in my opinion).
In terms of learning the app and it’s functions, I think Photoshop has less intimidating tools and panels and will probably be much quicker to get use to the basic tools and what they do. Adobe Illustrator can be overwhelming at first as it’s designed to do some very advanced designing and manipulation of graphics, but if you learn how to use the basic tools first and build from there it will become less intimidating quite quickly.
If you have a general desire to learn and you're ready take on the challenges associated with learning anything new then you could tackle either app. But if you find tech stuff a little intimidating then I would recommend starting with Photoshop.
Having said all that, any one of my Creators is a great way to learn either Photoshop or Illustrator - I designed them to be super easy to use even if you are a beginner. You can start with creating just the basic Scene or Character and expand to more advanced editing as you get more comfortable with the app.
Have a look at this tutorial for the Magical Scene Creator where I walk you through creating a scene - I use Adobe Illustrator and hop over to Adobe Photoshop if the steps are different, it might give you an idea of which app seems easier to use.
Here’s a quick fun post I wrote on why I love Illustrator.
Hope that helps with making a decision!