The former Oranje-Vrystaat (Orange-Freestate) was the heartland of the white Afrikaaner population and therefore most people in this region still speak Afrikaans as their first language. It was one of the first independent states, before joining the South African Union and the people here still live up to the voortrekker traditions of braaing and the Afrikaaner lifestyle. The economy in the Free State is not very strong and there is little farming due to the Karoo vegetation.
Also Afrikaans is still the first language of many people, most will definitely understand and speak English, although they might have a bit of an accent.
The N5 only serves as a connection between the N1 and the N3.
Best by car, as there are little means of public transport and great distances between each of the towns and cities.
Always have enough water with you, in case your car has a break down. Tell your last hotel where you are going to and which route you use, especially when going into a less populated and rural area.