Fares will depend on the journey being taken.
Children under the age of 5 years travel free and with child fares for those aged 5 to 15 years being half the adult fare.
Various railcards are available providing savings of one third on the cost of fares.
National Railcards:
Senior Railcard for the people 60 years and above
Family Railcard valid for up to four adults and four fare-paying children
Two Together Railcard for two named people travelling together
Disabled Railcard for people with disabilities
16-17 Saver for young people aged 16 and 17
Young Persons Railcard for 16-25 year olds
26-30 Railcard for people aged 26 to 30 years
HM Forces Railcard for members of the Regular Forces or Volunteer Reserves or a spouse/civil partner of a member
Veterans Railcard available to everyone who have served in HM Armed Forces or Merchant Mariners who have seen duty on legally defined military operations
You can purchase some railcards (valid for one year) at a staffed station. Alternatively railcards can be purchased online, where there is an option for a three year card at a reduced cost.
More Money Saving Tips
Duo Tickets are available for journeys on selected Northern routes, including the Tyne Valley Railway. These give a 25% saving on the fare when two people are travelling together. More details available on Northern's website.
Advance Purchase tickets are available for some journeys along the Tyne Valley Railway and for many journeys throughout the country. These single tickets are available in limited numbers and are valid for a specific journey at a specific time. Usually they are available 12 weeks in advance and the earlier you book the more chance you have a making greater savings. More details available here
Rangers and Rovers provide the passenger wishing to explore an area some great flexibility of travel within the eligible area of travel. 
Prices vary depending on the product purchased with railcard discounts available. They can be purchased at booking offices, at ticket vending machines or from the conductor on the train.
The full list of Rangers and Rovers available throughout the country can be found on National Rail's website