Solid advice from everyone here. I’d definitely go for the membership package too (I’m a Brit and frequent visitor). Main advantages in addition to those listed are the nicer toilets and the TVs showing activity around the course. So if it is heaving with rain you can sit in a tent being served drinks and watch all the action on the course in comfort.
Traffic is, as others have said, horrific if you aim to arrive ‘before XC’. If you consciously arrive waaaay earlier than you need to (assuming you are driving), you will breeze in AND get parking much closer to the tradestands. The car parks are deep and arriving late can mean you not only queue for a long time to get in, but you also then have a long walk to get to any action.
Budget hotel chains here are pretty solid - Premier Inn and Hol Inn express probably being the best. Travelodge is good if you find a new one or recently refurbed (they do charge for wifi), Ibis is functional but that is all. Old Travelodges can be pretty awful. All work on earlier = cheaper.