Repossession Houses

I know that in the UK, there are repossessions and such where the houses are sold off via auction. How would I find out where they are or if there are any in my area? Also, how would I go about bidding? Is it difficult to do this? Would I need a loan/mortgage in place before bidding? Please answer all these parts of the question and tell me any other information you know. Thankyou.

I just read that a bank held an auction of a bunch of properties in
Las Vegas, and the bank accepted 90% of the offers. I am guessing that
the people who go to these auctions are investors with cash, right?