Where can I kitesurf?
Anywhere there's water and also on mountains, with snowkite.
Is it possible to ride upwind ?
Yes, with the new materials that are coming out and with proper learnings.
Which wind conditions are most preferable for kitesurfing ?
You should never kite with a land wind that will take you out at large. The best winds are the ones parallel to shore. Do not kitesurf when the wind is too strong for your knowldge or if it is inconsistant.
How to change directions ?
By balancing your weight on your heels or with your kite.
How do I brake ?
Pressing down on your heels and changing your flight so your're going up wind will help you brake.
Should I kitesurf when there is alot of other surfers out there ?
You can, but you should respect the priority of the other kitesurfers. You need alot of space for kitesurfing so try and keep your distances.
Do I need a license to kitesurf ?
No, but one is available and you can benefit from a special insurance.