Is the White ink that is available in the market are all transparent ink? I want a a opaque (thick) white ink for printing. is that possible?
There are commercial inks that you would need a business licence and tax form to obtain. Since you may be using it for home use you would typically be getting a water based ink. The best option for you may be going to Hobby Lobby. They do have "do it yourself" home screening kits. Example here and white here From experience they are typically not transparent BUT you can dilute them to be transparent.
If you are printing on a dark garment, such as black, it is common to make two passes with white for best quality. Note that if also printing on dark garments its a good practice to lay down your whole design with white so that the colors will pop. Video explanation.