It doesn't look like 'sourcePt' does have a source, you're making up that variable in the expression.
The SetParameter function operates as follows: SetParameter (index, value) - (source), meaning that where you currently have 'sourcePt' should be an object.
inPts = arcpy.GetParameterAsText(0)
distance = arcpy.GetParameterAsText(1)
If 'sourcePt' does actually have a value associated with it (which from the code you've provided we cannot tell) then please include that as well.
mxd = arcpy.mapping.MapDocument("CURRENT")
df = arcpy.mapping.ListDataFrames(mxd)
arcpy.env.workspace = "CURRENT"
csvFile = r"csv location"
arcpy.TableToTable_conversion(csvFile, "database file save location")
# Set the local variables
in_Table = r"database file save location"
x_coords = "x-coordinate header from csv"
y_coords = "y-cooydinates header from csv"
out_Layer = "layer name"
saved_Layer = r"lyr file location and name"
prjPath = "coordinate system location and name, if needed"
arcpy.MakeXYEventLayer_management (in_Table, x_coords, y_coords, out_Layer, prjPath)
# Add layer to mxd
addLayer = arcpy.mapping.Layer(r"lyr file location and name") #same as above
arcpy.mapping.AddLayer(df, addLayer, "BOTTOM")