excel formula help 'if this name and this event next to that name look at the date ....

Try ..

=IFERROR(IF(INDEX(Sheet1!$C$2:$C$5000,MATCH(1,($A2=Sheet1!$A$2:$A$5000)*(B$1=Sheet1!$B$2:$B$5000)*(Sheet1!$C$2:$C$5000<>""),0)) < TODAY(),"x",""),"")