What are the mandatory schema, well there is no mandatory schema you have to use.
Resources you will find useful:
https://search.google.com/test/rich-results - To test a page and see if its eligible and to see any warnings or errors in your rich snippets.
I would suggest you use the following schema's
There are probably a few more you may want to use..
https://schema.org/ -- for more info on what schema types there are
Then use the Google testing tool on the # 1 competitors for your search terms and test their pages and duplicate what you see if it is appropriate, at least till you understand schema much better.