Transmission slipping and motor smokes when starts .Chevy Avalanche LTZ.

Check your trans fluid level and condition. If it's low top it up, if it's black you may need a trans rebuild. The engine smoking could be bad rings, valve seals, pcv system issue. Both of your problems will need a complete diagnosis. We won't be able to tell you exactly what's wrong with the car without looking at it. Use this link to find a good shop near you. https://repairpal.com/repair-shops Alex