“Fun” and “Funny” are two adjectives that are often confused.
“Funny” means that something is comical and it makes you laugh.
For example: “That was a funny joke.”,
“I think Louis CK is the funniest comedian”,
“My dad thinks he’s funny but he’s not.”
“Fun” means something that gives you enjoyment.
As in: “It was fun spending time with my sister.”,
“That soccer match was really fun.”
or “That was actually a fun English class”.
A problem is that funny things are usually also fun. If you see a hilarious comedy movie you might say:
A) “That movie is funny”
B) “That movie is fun.”
But what you’re really saying in A) is “That movie is funny, it can make people laugh” this is a quality you think the movie has.
In B) you are saying “Watching that movie is a fun experience, it can give people enjoyment” this is a feeling that people can get from a movie.
We wouldn’t usually say “That action movie is funny” unless it’s main focus is comedy, usually they provide fun through special effects, fights and explosions.
f you say “My friend is fun” it means that you and others get enjoyment from spending time with them. “My friend is funny” means they have the ability to make others laugh.
It’s possible for your friend to be funny, (they tell lots of clever jokes), but not very fun (the jokes are mean, or dark, or sad and don’t give you enjoyment).