If the stores address is formatted correctly in Store Information Setup the state your store is in will automatically be used for all new customers when loading new customer records.
The city state zip line should be formatted as follows in Store Setup.
City, ST zip
Eustis, FL 32726
If you format as above FL would be used for the state for all new customers (you can change manually if the customer is in a different state.)
If you DO NOT want the state to fill in automatically format it like below (no comma after the city):
City ST Zip
Eustis FL 32726