To Photoshop a picture on YouTube, you will need to use Adobe Photoshop.
There is no definitive answer to this question. You can use a variety of methods, including online tools and services, to create a YouTube profile picture.
There is no definitive way to make a professional profile picture. You could use a photo of yourself taken in a natural setting, or take a picture of yourself that shows your best features. You could also choose a photo that captures your personality well.