@sacboi wow thank you but I'm not that good yet lol.
I use a wacom tablet. Still working on my eye/hand coordination but slowly improving. I used a reference image, drew the outlines, then filed it in with colors. My drawing is one layer, the colouring is another layer and the background is another layer. That's the beauty of digital painting.
The mixing of the colour is simply how much pressure I put on the tablet while drawing/ painting. There are paint mixer brush tools in affinity. Can't think of the name off the top my head. I'm new at this too. It'll help with blending your colours.
Brush wise I used a few under the acrylic brush tab. Can't remember now because I was trying them out.
Hope this helps. There are a few good videos online. Go on you tube and search painting with affinity photo.