Never try to tune a cold engine. If it runs right once it’s warm then you probably have it set right. It’s just idling high because it’s cold. Also, air leaks tend to be more problematic once the engine is up to temp. Then it overheats and bogs.
It wouldn’t hurt anything to seal up the carb and backplate though just as a precautionary measure. I seal new engines before I ever even fire them up.