Imagine this random country. "Yolistan", it is a new country that appeared after a war/revolution/independence/whatever.
The currency it's the "Yolo"
Yolistan needs to import resources to start again the industry, for some time they are not able to produce enough raw materials so they decide to change their currency rate to 1:2 (Yolo/Dollar) to favor Imports.
The First Question is,
Where could this country acquire dollars at such rate or how they do it?
Yolistan(yolos) wants to buy Iron from the US(dollars) do they pay is Yolos or they have to buy dollars first?
After some time of importing goods, now they are able to supply themselves so they change the Yolo to 2:1 (Yolo/Dollar) to favor Exports
The Second Question,
"What happens to their economy and currency if that country changes the rate constantly to favor Exports/Imports?
Thanks for the interest in this question.