Sure, here are the correct forms of the words in the brackets:

1. You can have your goods delivered to you quickly and conveniently (convenience).
2. Bargaining is a norm in Vietnam, especially in local markets (bargain).
3. This grocery store sets a kilo of potatoes at a fixed price of $1.30 (fix).
4. Online stores usually enable shoppers to use "search" features to find specific models, brands, or items (shop).
5. There is always something new and colorful in this store for kids (colour).
6. Online shopping is a great option to look for rare and unique items (rarely).
7. Viewers can see what products are available for sale when visiting our online store (sell).
8. This workout studio sent me a complimentary offer to encourage me to buy a new package (compliment).
9. Before you make a commitment to the deal, you should make sure you have proof of purchase (commit).