Please help me on setup smartfade 2496

There isn't much to it with a few devices.

1. The SmartFade has a "DMX512 OUT" jack in the back. That's the female 5-pin one. Male ends always point towards the console.
2. The first cable goes from the console OUT to the closest dimmer. Yes the closest and most convenient to plug in, numbering and control is completely separate from wiring.
3. Each dimmer has 2 jacks, a DMX512 IN and a DMX512 OUT. The cable goes to the IN.
4. Another cable goes from that OUT to the next IN. Be a bit gentle with the plugs and jacks, those thin pins can be bent.
5. Repeat for all your dimmers, lights, effects or whatever is DMX controlled. Most folks call it 'daisy chain' wiring.

Each dimmer will have a "starting address" setting. Check the manual for how to change it. That dimmer will be controlled by its starting address and as many other addresses as it has dimmers. So if you have 3 dimmer packs with 6 dimmers each set then to #1, 7 & 13. The last dimmer in the last pack will be 18. And there you are, 18 dimmers controlled by channels 1-18

There is a lot to know about 'patching' and setting cues and all. So read the manual, watch the SmartFade videos and play around until you feel comfortable. And ask more questions here as needed.

Oh yes, this is the first of a nice series on the theory and practice of DMX512.  https://youtu.be/z3jM_rbILhs