Silverstone GP spectator experience?

My good lady has suggested that I take her father to Silverstone for Qualifying on the Saturday … I honestly have no idea what that experience is like! Roving grandstands on Saturday seem to imply you can sit in any stand, but my guess is that you’d need to be in place early in the day and then don’t move. He’d need a seat, he’s 76 and can’t stand/walk around all day.

And parking … how many miles will we have to walk?!

Guidance appreciated!