'Take on' has a few meanings. Here is a link which can tell you what it can mean: https://www.merriam-webster.com/dictionary/take...
If you 'put forward' something, it means that it should be considered for something. For example:
'He has put forward new peace proposals'
When something 'falls over' it falls to the ground. For example:
'If you fall over you will hurt yourself'.
'Fall off' means that something is falling from on top of something. For example:
'If you fall off your bike, you will hurt yourself'
In this case, you are 'falling off' because you were 'on' it, but then you fell 'off' it.
Please feel free to ask for me to clarify if I wasn't clear :)