Hi,
I think the answer is “not much”. But with help from forum members here, it could take you a lot less time to follow some of the recommendations on this forum than to make a random start on Youtube.
The link below is to a post by a forum member in which I have tried to set out the logical journey that I think anyone interested in Forex should be taking.
My own journey into Forex started in around 1988, but seriously in 2010. And I must be pretty useless at it because I still have not found the holy grail of being able to consistently trade with an edge.
I had watched about 20 videos created by what is referred to as the NNFX method until I realized there was a website that put those videos in chronological order. Once I had found the website, I then proceeded to spend about 100 hours writing a trading plan following that method.
In summary, I have found BabyPips to be a good place to start (click the Education tab for a well structured self learning training course called School of Pipsology. Followed in the intended order of learning that will save you a lot of time as well. Do the quizzes - the next time you log on it will keep track of your progress.
Best of luck with BabyPips and with Youtube videos. I use both extensively.