I haven't uploaded on you tube for years since my now 12 year old grandson was into Godzilla! But yesterday I downloaded the app and got into it, posting Zoey playing with her piano and baby toys.
Let's see sounds like you are already registered with you tube?
I would download the app anyway. They have made it pretty simple, even slowees like me finally figured it out. You have to give permission to let them download your camera pics and vidios first. Something will pop up..This is coming from my ipad.....
That done, column on left click on "my channel" arrow to the right is the upload it will bring your vidios up. Choose one , it will play first, click on arrow in upper right hand corner, and make sure you click on "view as public" so everybody can see it.otherwise if you get in a hurry like I did it leaves it on private and you have to go back and DELETE it to re upload it.
THEN you click on arrow in upper right corner and it starts uploading , can take awhile.....after it's uploaded , play it and in upper right corner in screen area there are 3 options...click the middle one, and find "copy link" at the bottom. Then go back to yorkie talk and paste.
Hope this is the same for you.
Zoey playing piano - YouTube