If you visit London make sure you keep your ID,credit,debit cards and money well hidden from pickpockets..I'm pretty canny at hiding my money these days after being done twice by them in London..
Otherwise the only thing you have to worry about is the exorbitant prices for food and drink...especially a pint or a cuppa.
Transport is cheap and easily found and there is so much to see and visit.
However if you can bear to get to London...can I suggest you go a little further south and visit Historic Portsmouth..the birthplace of Dickens,home of Nelson's Victory and The Mary Rose and the Warrior with access to the Isle of Wight...Which is a wonderful touristy place to visit...Blackgang Chine,The Needles Lighthouse,Osborne House(Queen Victoria's seaside home) and innumerable attractions too many to mention here...
