how do i buy flames do i need to buy flames texture to use the flame i bought form a guy ?

You don't need flame particle texture to use a flame, you just activate the flame item.

to buy flames you or forge it by yourself, or buy it from other player. The flame will be in your desactivated inventory as a normal item.

to activate it just click the red activate.

for customization you can use an OPTIONAL flame texture item, this item will change the particle or your flame.

and from where do i get the flame item

Ah, missread your question.

You can get the flame item either by buying it from another player or forging it yourself using Ctrl+L while ingame.
When forging the flame you move the sliders to change the settings. When you get a flame you like you press create, and you'll be told the price. If you like the price you press create and it'll be forged if you have enough tc.

Also, you can buy premade flames here
http://forum.toribash.com/forumdisplay.php?f=366