bonjour
1- I would get a card for a bookstore <em>(at the shopping center)</em>
<em> </em>Je voudrais acheter une carte-cadeau pour la librairie au centre commercial .
<em>what it really means = I would like to buy a gift card for the bookstore at the shopping center ....... I didn't get what you were exactly asking for ....</em>
<em> </em>
2- They would have to go to the bookstore, the jewelry store, and flower shop.
Ils devraient aller à la librairie, à la bijouterie et chez le fleuriste.
3- A good amount to spend would have to be a few hundred dollars.
Un montant correct à dépenser serait de quelques centaines de dollars.
<em>OR better ==></em>
Quelques centaines de dollars serait un montant correct pour des dépenses.
4- I decide what present I am going to get for a person by thinking about what would be important for them.
Je décide quel cadeau <em>(je vais acheter =) </em>acheter pour une personne en pensant à ce qui serait important pour elle.
<em>you don't need to write "je vais acheter", this makes the sentence too 'heavy'.. "quel cadeau acheter" is enough and means the same..</em>
<em>by thinking about = en pensant à</em>
hope this helps ☺☺☺