Hi leusajones1984, welcome to the community.
I must say this sounds like quite an undertaking that has tons of questions you have probably already thought of.
Almost every country has their own form of money currently in use. And the value of each country's said money varies by large degrees at times. How would you implement a single currency for use everywhere in the world? You would have to get every country to be in agreement to this new currency. I see that, in and of itself, as an immense task that will take years to complete, IF you are even able to get all countries to agree that a single currency would be beneficial to them. And, what would this currency look like? How hard is it going to be to disperse it to the people?
These are just a few of the thoughts and questions off the top of my head. I'm sure there are more and we'd all love to hear your thoughts and ideas on this,