Ok my bad. As i guessed, it was a very very stupid error : I didn't notice I was supposed to use quotes in the declaration of the new body...
Now it works for me to, thank

Hello, i'm trying to use this https://love2d.org/wiki/Body:setLinearVelocity and this https://love2d.org/wiki/Body:getLinearVelocity but i don't understand how they work. The "getLinearVelocity" function always returns me zeros. For example, this love.update function : function love.update...