Ambiguous is an adjective meaning unclear, vague, confusing or capable of being understood in more than one way:

• The wording of the section of the law under discussion was ambiguous and therefore hard to interpret decisively.
• The ending of the film was ambiguous so that many who saw it were puzzled about what the director had intended.

Ambivalent is an adjective which means being uncertain about how you feel or having two opposing feelings at the same time:

• He wanted to tell the truth but at the same time was ambivalent about giving evidence in court which would incriminate his brother.
• Many people have ambivalent feelings towards climate change, on the one hand wanting to preserve the earth’s resources but on the other hand wanting to benefit from the many energy guzzling devices available.