If I wash my hands and changes clothes after smoking, will the smoke my body hurt a baby/child?

Yes. You can never fully remove the smoke particles from your skin.
Decreases volume . It is well known that smokers lose some sense of smell & must quit for 5 days before they will detect the lingering smell on their hair or clothes. I applaud your effort to reduce babies exposure to smoke, but you will still have a baby with nicotine in their blood & urine as long as anyone in their life smokes.Be prepaired for the crib death risk, ear and lung infections as they will come.