I see you are making the trip from Austin to Silverstone for the WEC. I sort of did the opposite trip for the 2013 Austin F1 race.
I was at last years WEC at Silverstone and be warned it could be absolutely freezing. A bitter wind can cut across the circuit and it can be tricky to find a grandstand that shelters you.
One of the Village grandstands is usually open for WEC and this gives a great view of the loop and in the distance Becketts and Stowe.
Facilities are OK but unless you are fortunate enough to be in hospitality it can feel a bit old school.
The old pit complex is used for the F3 teams and this is great place to get up close to some cars and talk to the young drivers.
The circuit is a lot larger than Austin and will take a few hours to walk round but there are regular shuttle busses to take you to the best viewing points. Plus the buses can be a welcome bit of warmth if it happens to be a cold weekend.
I am sure you will have a great time and I hope that you enjoy exploring silverstone.