Do I have to have any previous experience to take voice lessons?

No. The lessons cater to the student's individual needs. You can be a complete beginner and still take voice lessons.

Yes. Having trouble singing in tune can be caused by not having control of the voice or an ear that lacks the skill to pre-hear the pitches. Both of these things can be taught. Some people aren't even aware that they sing out of tune. If you know that you do you're probably ahead game and will be more receptive to learning how to improve your intonation.

Yes. Smoking or exposure to second hand smoke, can dry the protective mucus which surrounds your vocal cords. The vocal cords can become inflamed. Drinking lots of water will help to some degree. This doesn't mean that you can't sing if you smoke but you should know that it will affect your voice and the sound that you produce. However, if you wish to be a classical singer, don't even think about smoking. The demands of serious classical singing require the healthiest of vocal folds possible but don't take my word for it. There is lots of information available on the internet or you can consult a voice care professional such as a speech pathologist.

Stay healthy. Drink lots of water. Eat healthy foods including those that are water rich, exercise regularly and make sure that you get enough sleep. Be kind to your voice. Don't try to sing or talk excessively if have a sore throat or feel run down.

Yes, this is very harmful for the voice. Over a long period of time this could lead to serious vocal damage. If you find that after singing for long periods of time or even short periods of time, that you are feeling hoarse, then it is very likely a problem with your vocal technique. You may be pushing or there is a lot of tension in your throat when you sing or perhaps you are singing in a range that is not comfortable for you. A good vocal teacher should be able to help you with this. Singing high notes, if approached correctly and if they are within a comfortable range of the singer should not cause the voice to become hoarse. Singing in general should always feel comfortable and easy and the throat relaxed no matter how difficult the repertoire. Hoarseness can also be caused by trying to sing through a sore throat, a bad cold or other illness. Other factors to consider are any medications you may be on that may dry the throat or an underlying medical condition. You can consult your family physician about these concerns.

My understanding of coffee or caffeinated beverages including many pops is that they dry out the throat and should not be consumed directly before singing. If you drink a lot of these during the course of the day, you may want to drink a lot water to make up for it. Of course cutting down on your intake of caffeine would be ideal. Some recent studies claim that if you are a regular coffee drinker that coffee doesn't dry you out but I do not know enough about these studies to make any comments about them. You may find information about this on the Internet. One thing you can count on for sure is that drinking lots of water on a daily basis is good for the vocal chords. But don’t take my word for it, try it and you will actually feel a noticeable difference in how your throat feels. There are various ways to make water more interesting by adding some citrus slices or making hot or cold herbal teas. If you need a bit of a lift try a nice peppermint tea.