Hi @Engelah,
The issue you are seeing is that the render has cracked off in the bottom corners.
I'd suggest using How to repair a rendered wall as a guide for this repair.
With the second image, the crack tells me that there is a section that is no longer sticking to the surface beneath. It would be best to break off the loose render before filling it and painting it. The other two repairs would be fine to just tidy up, then fill.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
