A good background of applied finite element method will help. That means to learn from the first principle, then material properties, response to load applications and relations. Look up YouTube lessons for help. There are lots of resources.
Firstly, you can learn from the tutorial manual of the software, through each example you will learn how to use different features. For specific information regarding any item, you can use the Reference manual. Finally, the scientific manual is very helpful to understand the theories behind each item. You can all these manuals on the software website.