Im not being able to select any vertices, edges or faces

You mean you can’t left click and drag to box select?

Do you have any 3rd party add-ons enabled?

Or maybe Sana @Roxie ,

You have the wrong Selection Mode enabled, like Subtract, for instance:

Thanks for sharing the video Sana. It may be what Martin says. Also I see in the outliner you have the reference image selected. Make sure you only selected the mesh and then go into edit mode.

Can you give us more context please? I don’t know exactly what you mean by command key. Are you rotating? When your performing what operation are you trying an angle? The A key is for selecting all or deselecting.

Hi Sana,

the Knife Tool takes some getting used to.

Maybe practice on the Default Cube a bit until you get the hang of it.

Press K, then Enter and then you can press A to constrain to an Angle (increments of 30° by default). Pressing A more than once cycles through different options (Screen/Relative/Off/Screen…)Screen is the one you probably want here.

Watch the options at the bottom of the 3D Viewport:

That’s an older Blender Version then 😊…it used to be C …they changed that to A in 3.0