Are there decent to use OSS tools? I see some SkethcUp and others recommended.
It doesn't need to render things realistically but would be nice if it can tell you that some pocket holes are going to run into each other, for example.
I’m sure there are others in this space, but I don’t know of any names off the top of my head.
In the OSS world, I believe the best contender in that space is FreeCAD. I've yet to try it myself.
In the OSS range:
FreeCAD, Blender, OpenSCAD are some helpful OSS. Even though none of those are ideal for Woodworking you could learn a lot from just using them.
Some free as in beer (or free trial) software would be:
TinkerCAD, Fusion360, SketchUp, Carveco, and Rhino.
It is pretty normal for Professional users to use a bunch of different software packages to use the best parts of all them.
To put it another way, picking the right 3D software is probably a woodworking XY problem. Furniture can and is made without it. Good luck.
It's free and fairly easy to use.
I've been using it for years. I used to develop solid a modeler but I have't used many others so I can't really compare and contrast.
Doesn't strictly answer your question, but if you're looking to make "simple furniture" 3D modelling is not strictly necessary, you can do a lot with a few simple measurements and 2D-designing.