Once the fire gets going in your fire place there should be really no smoke coming out of your chimney.
When you have white smoke coming out of your wood burning fireplace chimney it usually means that your fire is not receiving enough air.
You may need to open up your damper on the fireplace if you have one and allow the chimney to suck more air out of the fireplace which helps the wood burn better.
If it's a wood stove then you need to open the air vents on the wood stove to allow more air to come in or crack the door of the wood stove open a bit until the fire in the wood stove gets going.
Then close the wood stove door.
Any smoke coming out of a wood stove chimney or wood burning fireplace chimney should be almost colorless and thin.