I am trying to tweak topology according to the reference image to practice a little, but I am not even close to recreating the sample examples; For this reason I seek some advice regarding this topic.
guide examples:

This is my attempt but I don’t know how to recreate the edges

This is an example where I try to recreate the topology of the rectangle, but the union at the edges of each Face fails. I used the 3DFace command and then the join command but welding was not achieved correctly at the edges. subd problem join.3dm (32.8 KB)
what am I doing wrong?

Hi Eliel
The source of the error is where the point from one edge just lies on the other edge. Such areas do not join if you create 3D faces. Make the points lie on the points but not on the edges
In general when modeling try to create quadrangles only