You can find a trainer in Kingdom Come Deliverance to have facilities and save time in the main quest and finally be able to avenge the death of your parents. However there is no cheat codes strictly speaking in the basic game.
To progress faster, you can:
– steal a horse to travel distances with greater speed and without having to deal too much with the endurance bar,
– steal the maximum of caches,
– get the maximum amount of objects from the bandits that you trounce,
– find all the treasures,
– you can also skip dialogs that last an eternity with the Esc key,
– you can practice fighting with Robard for better statistics,
– buy the best armor and sword in Rattay to be well protected during clashes,
– sell and buy always in the same shops so that the merchants are never out of money,
– you can skip the side quests that stroll you from point A to bridge B and vice versa.