It sounds like so far you have been doing the right things.
To transfer your sketch to canvas, maybe you can use the grid method. You may want to look it up online, but in a nutshell, you draw a grid of squares over your sketch and draw a proportional grid on your canvas. Then you focus on one square at a time and draw the image on each square on your canvas until the entire image has been transferred. Keep the grid lines light, and when you're finished, you can erase or paint over them, and start working on painting your landscape. I hope this helps.