E and my friends will be driving from Begas to Big Sur on Sunday. We would love to go through poppy field, but our time is limited. What is the estimate duration ( minimum) of poppy field visit? How much time should we expect to spend there? ?

You need an hour at minimum if you arrive around 8am.

There are a few different hikes you can go on but if you are just wanting to see them quickly you could take a quick look even from the road. Best to get there earlier if you can cause it gets real busy. I went 2 weeks ago and spent about two hours. Could have stayed longer and hiked another trail. If you don't have that much time just seeing them is amazing