Hello Kathy.
Nice intro. Lots of people ask similar questions to yours when they join, so it is a good idea to go read the replies to some other newbies threads. Essentially, you can go almost anywhere. Typically we discover abandoned buildings simply by getting out there and driving around / catching public transport and keeping our eyes open. Also, news stories, places closing down and so on.
We have an unwritten rule that WE DO NOT SHARE LOCATIONS WITH THOSE WHO DO NOT SHARE WITH US.
What that means is you need to give before you get. Tell us and show us what we've you've explored first please.