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

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: