Bordeaux is a very nice city ! It isn't just museums even if there are museums, actually i'm living in Bdx and i've only visited one or four of them ^^
There are a lot of places to hang out : Jardin Public, Les Quais : the quays along the Garonne with bars, restaurants, coffees... which is called Le Quai des Marques there are also shops and the quays in front on the Place de La Bourse with a water miroir where kids go to refresh in the water. Quays are very long and you walk along the Garonne is a very nice walk especially during summer times. You can also just hang out on the street at Place Camille Jullian, it's nice. You can also have a coffee at the Grand Theatre.
Places to go shopping ? Everywhere :) There are so many different places that you will need more than a day to go everywhere !! There is a huge pedestrian 1km street with only 230 shops :p !! You will find what you want for sure ! This street is called Rue Sainte Catherine and is in the city center. There are also around that street other streets with lots of shops, like Rue Porte Dijeaux which crosses Rue Sainte Catherine. There is also Cours de L'Intendance which is another street crossing with rue Sainte Catherine. But you cant get lost, you'll see there is so many people that you will quickly understand where you should go ^^ There are famous shops like H&M, Zara, Promod... but also small shops where you can find lots of different clothes. You can also go to Meriadeck a big mall with lots of shops too. You can also go the Quai Des Marques along the Garonne. Places I told you are the best known and most popular but there are obviously other places in the city center.
If you want to have a drink with friends, the most popular place is La Victoire (it's the big place where Rue Sainte Catherine starts from). There are a lot of different bars, this is where most of students go on Thursdays (special student's evenings) during the school year but also during the summer.
If you want to go to the restaurant with a limited budget, there is a lots of different places but I'll recommend streets around Camille Julian and Place du Parlement Saint Pierre. It's a very nice neighborhood with a lot of restaurant with different specialties.
If you want to go to the beach, you'll need to take the train or the car if you have one because the beach is not in bordeaux but about 30 minutes by car from here, easy to go. There are different beaches, Bassin D'Arcachon, Andernos, Cap Ferret, Biscarosse, Lacanau.... During the summer there are buses that take you from the city to the beach for few euros.
And don't worry if you have friends living in Bdx they know what to do or where to go ^^
I'll tell you what i like to do for a day in the city center :
morning : shopping at Rue Sainte Catherine but more around Cours de L'Intendance and Grand Theatre cause i prefer these shops but that's up to you ! Then lunch in an organic restaurant near Pey Berland (this is where i get off the tramway to go to Rue Sainte Cath') or in a brasserie Place Gambetta near Cours de L'Intendance. The Brasserie is near the gastronomic restaurant called Regent, the menu is about 10e. Then i have a coffee somewhere depending on my mood ^^ and then a walk in Jardin Public to feed the ducks ^^ At night i like to meet my friends at La Victoire and we decide together where to go to have a drink, there are different options but we like to go to the Torito or to the Cale Sèche. Then we sometimes go to disco, to La Plage.
I really like my city ! I hope that you'll like it as much as i do ^^
have a look here : http://www.33-bordeaux.com/