Set the oven to 177°C. That's the standard conversion (350°F minus 32, times 5/9, is 176.7°C), and most ovens round to 175°C or 180°C in steps of five, so either works for most recipes.
If your oven only goes in 10-degree steps, 180°C is the usual choice. Baking times usually stay the same at that small difference, though thin items like cookies may brown a little faster, so check a few minutes early.
If the recipe is a convection (fan) setting, many guides suggest lowering the temperature by about 20°C, so 350°F would become roughly 160°C. Check your oven's manual to see whether it has a fan mode before you adjust.
