If you haven't already, check out the Help section via the In-Game Main Menu. After that, make sure you have tutorials and tooltips turned on.
The start of a new game gives a basic overview of things, if you read the text it has, but for new playthroughs your goals should be: Grinding, Achievements, Completing the Zones and discovering the optimal outcomes to encounters.
The game has a in-depth combat system, if you have difficulties understanding it after reading the tutorials and the Combat Intro tutorial that plays during your first battle, try practicing on Goblins, Brigands and Weresluts.
Food is best earned via the Inn, unless changes have been made that makes buying food easier.
Quick Save often, but also create new saves that you rotate to discover the consequences of certain encounters.
If you have trouble understanding encounters or difficulty dealing with food, use the Cheats option to enable the Encounter Viewer so you can replay specific Encounters.
Cheats disable Achievement gain, but you can disable cheats after using them to earn Achievements after the fact. With Cheats Enabled, you can actually skip all combat by choosing the outcome you want in the Outcome Displayer (Middle Right side of the screen during combat)