Rui,
In Australia, we have a nice mixture of cabin crew, both male and female. Qantaslink have many male flight attendants and do not discriminate. So do not worry, being male will not go against you what so ever.
I know that when you are not in the industry it's very easy to believe all the things you hear. Gee golly wiz, we all went through that stage, so don't worry.
Good luck matey, keep us all informed how you go.