Thank you for your answer, and your welcome :)
Yes, I just bought Affinity Designer and yes I do mean layout designing websites graphically with Affinity Designer.
Thank you for your advice on using tutorials that are focussed on other apps, I did not thought about that. However, it would be awesome to follow tutorials/courses on Affinity Designer (focussed on designing a website graphically) since I have no experience with these kind of apps.
Tutorials on techniques that are also used in designing a website graphically are also welcome.
I hope someone can help me.