A computer isn't essential  - any device (including smart phones or tablets) which can vide web pages should be adequate to view the course. 
Going forward, you may find the larger screen on a tablet or laptop easier than a mobile phone but you can always try it with the phone and see how you get on. It will also be useful to be able to print out song sheets longer term, although we can post you the initial sheets to get you going, if you don't have access to a printer.