Well dizziness is quite common when you start on flute, because you don't have the muscles developed that are needed to focus the air, so you lose a lot of it to the outside, and some to the flute, and overall just use way more air than you need to. As you become more and more used to it (within a couple of months certainly), the dizziness should go away. If not, be sure to talk to your teacher and a health care professional to be sure that you're not doing anything wrong with your playing, and that there is nothing physiological contributing to the dizziness. As for getting the sound, try taking the head off and practicing making sound with just that. It will help you learn how to use your airstream to produce a tone without the extra concern of fingerings and the like. And for the tonguing technique, be sure your airstream is constant, but is simply being interrupted by the tongue. Sometimes it helps to imagine you're playing a whole note (for a consistent airstream), but just sticking your tongue in there really quick to articulate. Hope that helps!

A good thing to do is practice deep breathing when you are NOT playing the flute. Do it in the morning when you're lying in bed, or right before bed at night (depending on whether you find the extra oxygen invigorating or relaxing <g>. Put your hand on your belly. Exhale fully, and then take a deep slow breath. Your hand should rise as your diaphragm moves down. Fill your lungs from the belly up. Then slowly exhale. Do this a couple of times per day. Once you're used to the feeling, you can do it any time--practice it both standing and sitting, as you won't normally play your fluting lying down.

BTW, I actually learned this when I was pregnant, not in flute lessons. But, it really is the correct way to breathe, and practicing it will help a lot with the lightheadedness, as long as it's simply related to your body getting used to the extra oxygen intake and/or the need to fully empty your lungs to complete a musical phrase.

<Added>

I have no idea where that winky face came from--the software obvious ate my closing parenthesis. However, I'm not sure I like what it implies about the previous sentence, so I figured I'd note that it isn't meant to be there. :)

try practising in a normal soft drink bottle... wether its empty or full, it always makes a sound. ...plus you get to drink it and practise breathing at the same time...