Well, if you are going to walk in the country, you need to be prepared for rough ground and possible change of the weather, so we recommend wearing walking boots or walking shoes with good soles. Take a waterproof and if it's the winter, hat and gloves can also come in handy.
Our walks usually involve a coffee stop but it's all self service so we suggest you bring a drink and a snack. People often bring a flask and water is a good idea at any time of year. On our longer walks we will have a lunch break as well so bring some sandwiches or whatever you like to eat at lunchtime.