Best thing is go for Rann Utsav which is going to start from Nov-Feb. Try to make you plan so that either you are there in Kutch in Purnima (beautiful full moon) or in Amavasya(beutiful twinkling stars).
Depending on area of interest, theres a lot to see in Gujarat. If you are interested in architecture then there are famous temples of Somnath and Dwarkadhish, Rani ki vav,adalaj step well , Modhera ; if you are nature lover then there are Girnar and Gir national park;if you love beaches then there is Dumas beach and many more. And in case you want to see everything , then I suggest to do that area-wise/district wise. Check out more on https://www.gujarattourism.com Hope this was useful. :):) happy journey!!
The Rann of Kutch festival starts from November and lasts till February. And also Visiting during this time will be good. You can check their official website to book your trip. http://www.rannutsav.com/