How do I make these?

I’m new to this whole thing and very excited about it. I got a tile printed and mounted but then I am overwhelmed by the number of pieces and parts without a clear path forward to actually make something useful. I see things in the background of the videos and say “yeah, I want to make that,” but don’t know how to get started. Show me how to make one of the things in the picture, what parts does it take, how do they fasten together and to the wall tiles. Then once I have that figured out I can start tweaking and experimenting. This would be SUPER helpful!!