Can't create rectangle on same plan as an existing CAD drawing

An architect friend gave me a floor plan workup in .dxf, including all the structural components of the building’s floor.

Now I’m trying to create structures on top of that in SketchUp.

I imported the .dxf file into SketchUp just fine, but the program is not allowing me to create INDEPENDENT rectangles on top of the original. Using either the Line or Rectangle tool, the program will not allow me to create the shape of my choosing - it’s forcing me to use inference points on the underlying drawing.

I’ve even tried creating a rectangle outside of the floor plan, then dragging it onto the floor plan. It automatically connects the new rectangle with points on the floor plan – seemingly without rhyme or reason.

Here’s what happens when I try to highlight the newly created rectangle.

I figure there’s some setting that will allow me to work exclusively with the new triangle - or perhaps as a noob, I’m missing some fundamental aspect of the program.

Any help deeply appreciated!

Select all of the imported geometry and group it so the stuff you draw on top of it doesn’t merge with it.

Grouping geometry puts it in a virtual container and provides separation between that geometry and new geometry. If you need to add to the geometry inside the group, open the group for editing.

You should spend some time with the Getting Started videos from the SketchUp site before you dig yourself a big hole.

hey thanks man.
i will definitely watch those videos in their entirety.

I really appreciate yr help.