How can I progress forward?

Replay old scenes to earn coins so you can buy decoration. The Flower value from the decoration will allow you to progress. You will receive the Flower value after construction is complete and you remove the red ribbon. How many more Flowers you need is indicated next to the flower icon. The higher the Flower value you purchase, the further you can progress. If you lack space on your island, then put some low-Flower items in storage and replace them with high-Flower items.