I bought it but i dont know how to make it so it would be seen

You need to make a flame using the flame forger. But making a flame using the forger costs you a lot of tc. Around 65k or something.

Flame prices vary on how you make the flame, you can also buy some in the item section labelled flames.

Like tempo said, the prices range I believe the lowest can be 35k.

yeah i belive i bought a flame texture

You bought a flame particle texture, that is what you want the particles of the flame to look like.
It has an effect only if you purchase a flame in flame forge.

how to buy the flame forger ?

You don't buy anything to forge flames, you just have to pay the price for the flame once you've forged it.

To forge flames press Ctrl+L, move the sliders, press create and then press forge in the popup window if you're happy with the price.