where can i found oak wood?
Oak wood is found in the forest.
Choose the option "Explore Surroundings" (I think this is the option caption, sorry if I'm wrong). It's a randon generated event, so, it depends on your luck.
(If you want a hint, craft some energy drinks before looking for oak wood since you'll be able to collet just 2-4 and you'll be tired already. Use the enrrgy drink opening your backpack to remove the tired status. You'll be able to collect some more without needing to go back to your place and sleep)