how hard will getting food be?
That would depend on your skills and where you are.
If you have the forage skill and are in the forests, you will pretty easily find enough food to survive just by poking in the bushes.
If you do not have the forage skill and are unable to kill wild game then you will be in trouble. Though I guess it's possible that fruit trees might be plentiful enough to happen upon one.
Where fresh water is plentiful, so will food be.
In the desert, you should bring what you need, I think.