[Mehere]

Does anyone know what this growth is on this driftwood? 3 week old 8 gallon freshwater tank. Should I be concerned?

 

[NearMeBettas]

That's biofilm. Totally normal especially in newly established tanks or on newly added wood. Once your cycle is complete and fish are ready to add you could get a few inca aka mystery snails and they will eat some of it.