this code only gave me patients and not visitors. However, I do finally have the solution. It is:
SELECT e.Event_Number, e.DtTm_Rcd_Added, ep.First_Name + ' ' + ep.Last_Name PatientName,
ev.First_Name + ' ' + ev.Last_Name Vistor, v.Pi_Type_Code, g.System_Table_Name
FROM Event e
JOIN...