Something is simple if it doesn't have a lot of elaborate parts, or is very easy to understand. The picture is of a very simple flower arrangement.
The opposite of simple might be elaborate, complicated or difficult.
A temple is a place that people go to serve or worship a deity or deities. Temples tend to have a distinctive shape according to the religion of the people who built the temple.
A wimple is a medieval era piece of headgear, worn by married women to cover up their hair. Wimples sometimes covered some of a woman's face and neck too.