Add Cube Free 3D model

Open Blender:*Launch Blender on your computer.*Delete Default Cube (optional):If there's a default cube in the scene, you can delete it by selecting it and pressing the Delete key or right-clicking and selecting Delete from the menu.

Add a Cube:

Press Shift + A or click on Add in the top left corner of the 3D viewport.Select Mesh and then Cube to add a new cube to the scene.Import the OBJ File:

Click on File in the top menu.Select Import and choose Wavefront (.obj).Navigate to the directory where your OBJ file is located, select it, and click Import OBJ.The OBJ file will now be imported into the scene.

Position and Scale the Objects (optional):

Use the transform tools (shortcut keys: G for move, R for rotate, S for scale) to position, rotate, and scale the cube and the imported OBJ model as desired.