It will be packed with Sunderland supporters getting on at Newcastle. Hull trains are very doubtful. Sunderland supporters again.
The only other option is Sheffield to Manchester, then train to London via Birmingham, and get off at Watford Junction. Then the train to Wembley Central.
Another option is to go by coach. Either the coach, you can book on the Blades website. You can go on a coach from Pond Street or Meadowhall.
If you can afford it, go down on Friday and return on Monday. If you're going by car, Watford Junction car parks are nearby. Best to look on the internet and book in advance as soon as you can. Or park on the outskirts of London near a tube station.UTB