If it is a spell that has an attack or saving throw, you should be able to cast it by clicking on the name in the attack panel in the center of the sheet. If you are on the spell panel, click on the name of the spell there. You should see the results of the spell in chat. Sometimes it will just be a description. If the spell is set up for it, it should roll attack and damage. Currently, the spell slots do not automatically reduce. You will need to click them manually when casting a spell. I think that the Beacon sheet can do that eventually. On the 2014 sheet, it requ ires a script. Let me know if this answers your quesiton.
