As an avid user of 'poop' phones, let me toss a wrench into this mix.
My devices are no better than yours, as far as specs go, and yet I am not having these issues.
You say that the apps you have on the device have no real important info, correct?
If so, this is good.
Because what I am going to suggest is the installation of at least one app, and possibly more if need be.
All that you need to free up is about 30MB for an app that should work great on your device.
So pick an app that you can easily rebuild, and remove it to make some room quickly.
With any luck, you will gain loads of space and be able to put the app right back again.
Luckily, I can provide a link to an older version of an app that I use- that should mesh perfectly with your device.
Keep in mind that cleaner apps have horrid reputations, and I only offer this one because it has no ads and that because of the age of your device the features of this app should prove extremely useful.
https://systweak-android-cleaner.en.uptodown.com/android/download/1633705
The cleaner and the duplicate finder are the most important, and the file manager will order things by size for you.
This app will allow you to see what is taking space, and delete as you wish.
Tap on any item to load it, to see if you really want to delete it.
Things like thumbnails kill memory space on devices like yours and mine.
If it turns out to be masses of thumbnails, let me know, and I will describe how to keep them from coming back.