If you setup the “Action Mapping” like told you, you would need to make sure that the Input is enabled for that BP.
The CharacterBP should be enabled by default, but if you want other BP to accept rightclick you would need to enable it’s input:
http://puu.sh/cVMUT/e49a865792.png
But this is not what you want, because now you can just rightclick everywhere and it would print “Hello”.
So better get the Hitresult under Cursor and do your stuff depending on the hitresult. Here i just printed the Hitactors Name. Maybe you should also use a branch and plugin the “Return Value” which is just true or false depending on hitting something at all.