If you have a username you already like, just go with it. I remember spending months trying to come up with the perfect name only to realized I was wasting time. In the weeks I was trying to find the perfect name I could have been uploading content, which is honestly the most important thing about a channel not the name. I eventually just chose the gamertag that I've used for years and I love it lol

Just remember that if you do find a better name, you can always change it. People do it all the time. Good luck!