Just as each state in the US has their laws about firearms, so does each country of Europe.
If you are planning a trip to Europe, go.
But do not take your firearm.
To get a concealed weapons permit is next to impossible. To import a firearm is expensive. And you do not want to get caught smuggling one in.
So what do you do? Rely on other things for self defense. Try not to look like an American tourist.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)