There are many Jewish communities in the UK, mainly in the major cities. There are a few Jewish girls here on the forum (Shalom!) I have found people very interested in Judaism, my friends are all very interested and love sharing the holidays and traditions with me and my family. My son goes to a Church of England School, but for Chanukah last year we brought in a menorah and a book about the holiday and everybody welcomed us. London has probably the biggest Jewish community in the UK and you should be able to find food, synogogues etc, however my only complaint is that the Reform Synogogues are, in my opinion, too frum for me. I live in Manchester where we also have a Jewish community, but I have found it a bit insular and haven't been involved in a Synogogue, however we do celebrate the holidays at home, and I travel back to my family in NY for the High Holidays & Passover if I can. Also, when my son was born the local Synogogue helped me to find a Mohel and we had a Bris, it was a really important moment for me and my parents.
North London, areas like Golders Green & Hampstead will have a big Jewish community.
I don't think you will find too much anti-Semetic sentiments, but of course, I can't speak for every situation you will be in! Good luck!!