Hello , I am new to C# and unity ,I am wondering how can I draw a straight lines using the HTC Vive Controller. Can I use Line Renderer and if so , how do I get a straight line. Thanks for the help 
Yes you can use Line Renderer.
https://docs.unity3d.com/ScriptReference/LineRenderer.html
Use set position with any two points and it will be a straight line. If you need a curved line you break it down into a number of smaller line segments.