Too deep, sorry but there are resources like ctrl + paint that achieve the same on a more friendly wise path

Hi Jon I'm a beginner at painting so I'm just focusing on blending two colors first, but I have a very hard time. I've tried different brushes to see the difference and worked with the pen pressure. I can not while blending getting rid of those hard edges. I'm always using the color in between after the first brush stroke and achieve to have the middle value. The best I can do is having a rainbow of multiple value but not a smooth gradient. Any advice ? Also I want to learn to do it manually before using the smudge tool to make sure I acquire the skills.