If you are having trouble accessing Scratch, there are some alternatives to have a go at listed below:
Code.org - explore some coding projects and activities - https://code.org/
Swift Playgrounds app - If you have an Apple Mac or iPad, Swift Playgrounds has a lot of puzzles and concepts to try and learn
Code Monster - This is a useful website to get a good understanding of code - http://www.crunchzilla.com/code-monster