Excellent question !
Well it depends what you are saying!
If you are talking about yourself, being a man, use the masculine form as you would when talking about any other man or masculine things.
Example:
John: Je suis marié. I'm married.
Henry: Ce manteau est beau. This coat is beautiful.
Jeff: Il est content. He is happy.
Here the adjectives marié / beau and content are at the masculine form
If you are talking about a woman or feminine things, use the feminine form.
Amy: Je suis mariée. I am married.
Mary: Cette robe est belle. This dress is beautiful.
Karen: Elle est contente. She is happy.
Here the adjectives mariée / belle and contente are at the feminine form.
If you need more clarification, ask here
Have a wonderful time learning French!
Angèle