Board Game Arena

I have only played Agricola a few times and I don't understand the rules very well. In my present game I bought a stone oven but I cannot do anything with it. What do I have to do to use it?

You have to take a 'bake' action. (Convert grain into food).
You immediately get a bake action when you buy an oven. (You may have missed your chance, or you didn't have any grain?)

Otherwise a bake action can be found on the 'sow and bake' (Grain Utilisation) action spot.
Lots of different cards give you a bake action in various ways.

----
Just looked at your turn based game - 8 beggars - ouch!.
You can also eat your veg in the hearth. There is a 'conversion' button top-right that allows you to do a variety of different conversion things at ANY given time. Even at harvest, after you take crops and when you have to feed. But this does not allow 'bake' actions.

Thank you, this makes it clear. I have used the sow and bake action so it works.