Texture and 3D

I have a problem with the textures I created a table with the Techne application and the texture that the application was doing and I put the touches to look like a dark wooden table but I don't know if I have to put it in item or block at the end I put in block and put .json to the table file since the file was java and java it was for the mod, so when I put it I do not get the texture well it comes out broken and I don't know if it is the texture or because it changes the name to json and if so, I don't know how to set the table with json I don't know how to set the table with json without changing his name