You can unlock additional locations within your village by satisfying certain conditions, as indicated below. If you have satisfied the conditions as stated and the new location does not become available, wait a few days. Some places will not appear until you have been living in the village for 7 to 10 days, or there may be an additional time restriction after you meet the other criteria. Most buildings must be obtained through the Public Works.
Club LOL - Upgrade Nookling Junction at least once, give Dr. Shrunk permission when he visits, and obtain signatures from six villagers.
Dream Suite - Visit Isabelle, who should be asleep in the Town Hall.
Fortune Teller Shop - Have your fortune read 20 times by Katrina, the visiting fortune teller, then talk to her again and the shop will become an option.
Garden Center - Plant or water 30 plants or flowers/trees, or pull 30 weeds.
Kicks - Spend over 8000 bells in the Able Sisters' shop.
Museum Shop - Donate at least 20 items (with one or more in each category) to the museum, and talk to Blathers daily.
Shampoodle - Spend at least 10,000 bells in Able Sisters' or Kicks and then wait at least 10 days after Kicks is built.
The Island Resort - Upgrade to a house, then talk to Tortimer at the docks and you can visit the island a day later.
The Roost Cafe - Donate 50 items to the Museum, and unlock the Museum Shop, then talk to Blathers 7 days after the shop's grand opening.