Hi Pierluigi
It depends on what you are there to see. Cars or drivers!? :-)
If you want o take pictures of cars for modeling reference, be in the paddocks early and late of the days, when the larger audience is already leaving.
Go there after the drivers have left ( with the autograph hunters ) and the cars are being worked on.
Especially don't go in the modern F1 tent area, when the drivers are there. You only have loads of TV fan folk and don't get to see much of driver or car. Waste of time :-)
If you mainly want autographs, you have to be around the cars when the drivers come and go with them, but expect lots of people with the same plan. Many also hang out in front of the driver's lounge entrance between Goodwood house and the upper ( F1 ) paddock. I don't know if that's successful...
You could go to the top of the hill where the cars wait after their run up the hill and the drivers have some time. Probably a good place for autographs with less spectators.
Generally it's not so difficult to get autographs, apart from the modern F1 folks. I never specifically tried but got quite a few.
For track action go down to start "straight" for at least an F1 run. ( That's around No6 in the linked map )
Another good spot used to be the hill running up to the flint wall ( between No8 and 11 on the map )
https://www.goodwood.com/flagship-event ... event-map/
