Another thing to know about house sales in general is that they vary greatly from state to state in the US. Some of the differences are based on the laws in each state, some are based on local custom.
For example, in some areas, it is expected that appliances such as refrigerators, stoves and dishwashers remain with the house (unless specifically stated that they do not), while washers and dryers do not. In other areas, it is expected that all appliances will go with the seller when they move.
In many areas, the new owners take possession the day they sign the papers to buy the house, and the buyers must be out of the house completely at that time. In other places, it is the norm for the sellers to have 2-3 days to finish moving out of the house. In others, it can be common for the sellers to rent the house back from the buyers for a month or so, until their new house is ready.
Most states allow for the initial offer for a house to include an inspection clause, where the buyers can back out of the sale if the home inspection shows serious problems with the house. But some people don't get inspections. Some states require real estate lawyers be involved, others don't.
This sort of thing varies so much that you might want to check out what happens in the typical Florida house sale, if the sale of a house is going to feature in your story. (I've never even been to Florida, so I can't help you there.)
Oh, and the word "Realtor" is trademarked by some real estate agent organization, so if you use it, it should be capitalized. But you can use "agent" or "real estate agent" freely.