First off there would be Lightworks, which is free with some limitations. It's a pure abomination and needs a lot of learning an rethinking if you're used to usual NLE software.
Then, what most people don't think of, there would be Blender. Actually a 3D rendering software, but also a very good, free/open source video editor. Like all software, it has a learning curve, but there are some really nice tutorials. Just search on YouTube for "blender video editing".
There is Microsoft Movie Maker that comes free with Windows. It is part of the Windows Essentials package that is available for the recent versions of Windows. I have found it is quite simple to use and able to perform the simple set of tasks you list.
There are a few online help guides and YouTube videos about using it. The nice thing is that as it is quite a simple too it is not so complicated to pick up the basics. I have used it for down car and motorcycle DVR footage.
You can use VSDC Video editor. It is free. You can add clips, delete a portion of a clip, add text wherever you want, move the text from one place to another, PIP (Picture in picture) is possible.
You can save in many formnats. This SW (VSDC) also works as convertor to convert the videos from one format to another.
This accepts images, videos, audios, etc.
You can also add, delete an audio at any portion of the video