Sheets is very versatile, but particularly good when looking at data. There are a few add ons and extensions that make using sheets easier, depending on what you want to do with it. Eg) Flubaroo is an add on that will grade exact answers for you and provide you with statistics. Doctopus and Goobric work really well together to provide you a great way of marking electronic assessments and providing students with feedback.
There are heaps more, just search in the add ons section and see what you can find. There are a few important basics that you should know how to do though: