I need help in Sofa mesh optimization

Look for game assets creation course or tutorial. It’s basically that workflow you’ll use.

these little courses are pretty decent :

https://www.thegnomonworkshop.com/tutorials/creating-props-for-games-vol-1 (paid) (Maya hardsurface focused)
https://www.thegnomonworkshop.com/tutorials/environment-modeling-and-sculpting-for-game-production (paid) (zbrush organic focused)

This one is from Wes McDermott, a guy who does the tutorials for allegorithmic. This is his full substance painter course. Very well explained.

https://www.lynda.com/Substance-Painter-tutorials/Substance-Painter-Essential-Training/496947-2.html (paid) (overwatch Tracer’s gun as a bonus). You could probably find all of the info scattered on the allegorithmic’s youtube channel though, but it’s all well contained and organised in this course.

My workflow would probably be different than ZacD though. If you are willing to sculpt the chair’s detail instead of modeling it in blender. (I’m not sure if sculpting is good in blender though)

-block out the shape in blender
-import in zbrush
-sculpt all details
-use zremesher to retopologize and create a clean low poly version of the chair, uv unwrap it with zbrush’s uv master
-bake the sculpted high poly into a normal map, bake the AO, cavity as well
-Import low poly and maps into substance painter
-Do you texturing, export maps with the unreal engine 4 preset.
-Import your chair and the texture maps in ue4.