I have moto e phone. It has inbuilt 2 GB memory. Of which, 1.6 GB is used by inbuilt useless apps. I have to constantly delete pics, and system cache, so that I can have basic apps like WhatsApp or telegram, without low disk space warning. I have inserted 2 years ago
Knowledge Junction:Answered in 843 mins
Given the specs I am assuming you are referring to the 1st generation Moto E.
It coes come with poor internal memory and has very limited options you can do.
1. You can use any USB OTG pendrive to directly back up photos etc. from phone memory onto an external device and free up some space
2. You could root the phone (not very difficult since it's stock Android) - but it does void your warranty. Once rooted you can delete all the bloatware (unnecessary apps) that are occupying space. Please note rooting comes with it's own set of risks and joys.
3. As a short term solution - when you are installing apps like WhatsApp etc. - just to facilitate the install - clear all the CACHE of large apps and then attempt the install.