The nightlife in Sana'a is not so rich as in the European countries. There are a couple of places that you can visit where you can grab a drink and something to eat.
The Al Bustan's Club is a small club that hosts a DJ that plays all kinds of music You can also give your list of songs to the DJ and he/she will play it. The selection of alcohol drinks is limited.
There are also manny coffee shops in Sana'a where you can grab a cup of coffee for a Starbucks price and enjoy a piece of cake. You can also have tea or fresh juice.
Sana'a is full of restaurants which offer a variety of food. It is always a good choice to visit a restaurant and eat some regional traditional dish.
You can also go shopping in Sana'a. The best place for that is the Jamal street where most of the shops can be found.