If they are hard leave them at room temperature to ripen. Citrus fruit and apples and grapes may be left at room temperature for a few days before they begin to spoil. Bananas should not be refrigerated. Bananas should be eaten soon as they are the most perishable of fruits and they should never be left wrapped in the cellophane. Fruit will spoil quicker in warm temperatures.
Most plants sold as houseplants have a tropical lineage.
Each variety of plants has specific needs. Some like sun and water some like shade and little water. You should be sure of the variety of plant that you have received and get specific care directions for your specific plant. In general when watering a tropical plant you should water thoroughly until the water seeps out the bottom of the planter. Do not let plants sit in water.