Hello, I got a problem here.. How do I use my set?? How do I activate it?

If you mean art for your tori, then you need to buy textures.

You can get them from the market or the shop

Also, of you're good at negotiating, you can get them even for cheaper on the items forum

I made a texture set for myself but I dont know how to add it to my tori,do I need to upload it or something?

you Need like MC said to buy textures after you do that you can upload the textures
you can upload them here: http://forum.toribash.com/tori_textures.php
It needs to be one of the formats though or else it wont be uploaded