Here's what it means (more or less literally -feel free to improve my English!)

There're many people who get worried to death,
They're indecisive,
Pale and shivering.
With all sincerity, I pity these guys.
I'm not like that
Because I don't worry.
No matter what you do and say,
It's better to smile
And to know always how
To be happy.

Refrain
I have my trick,
Never in my life does anything bother me.
I have my trick,
I keep my little heart as white as the white ermine.
Worries, thank you, it's all the same to me!
Troubles, so much for the worse, I don't care at all!
I have my trick,
It's trite but it's jolly, it's the main thing.

There are suckers who allow themselves to be ripped off,
They get squandered
By bankers.
Then they rush to the prosecutor to complain
And everywhere they cry
Over their misfortune.
Me, I'm not stupid enough
To lose my dough this way.
To save my bread,
I'm broke.

There are some [people] who don't know how to love the nice ladies/women.
Every time they get impassionate,
They make a big deal about it.
If their mistresses cheat on them, they shout "crime!"
And then, whack, whack, whack!
They wreck them!
Me, not one mistress
Ever made me distressed.
I always have, fortunately,
Several of them.