Hi there Dave and welcome to the forum
The following may answer both your questions.
Are you inputting the field name by selecting "Specify Field Name..." in the Send Mail Options dialog?
If so, instead select "Specify Calculation..." and in the Specify Calculation dialog input your email body along the lines of:
"¶¶Here are details of your task.
¶¶Name: " & Events::Event Name &
"¶Date: " & Events::Event Date &
"¶Location: " & Events::Location Name &
And you can setup the To: field the same way, but with this calculation
Substitute ( List ( events_eventscontacts_Contacts::Email ) ; "¶" ; " , " )
This will concatenate all the email addresses you are sending to, separated with a comma.
Let me know if any of the above needs additional explanation, or if you have any other question.