If you buy fresh wood from a felling, you should absolutely dry it. Birch wood has the advantage that it dries relatively quickly (often in about a year under favorable conditions, beech, however, often takes two to three years). But you should not burn birch wood damp, even if an old Scout wisdom is that birch wood also burns wet. However, this applies at the very most for bonfires. Birch bark can also be used well in the stove for lighting.