Why do I need to know ça va aller?
It is an extremely common expression which is said all the time in France and you will start sounding a lot of more native if you can start throwing it into conversation too.
What does it mean?
Ça va aller means 'It's going to be alright' or 'It'll be ok'.
So for example, if you're with a friend who is worrying about something, you could comfort them with the words: Ne t'inquiète pas, ça va aller. – Don't worry, it's going to be alright.
You can also use it in a different context.
For example, it's very common to hear people use it in a restaurant, cafe or boulangerie when they are asked if they need anything else.
In this situation, you could say, Non merci, ça va aller — 'No, thanks, that's ok'.
You can also turn it into a question, so you could ask: Ça va aller? to mean 'Will it be ok?' or 'Will that work?'