With smaller shows they close during judging -no visitors. So you would be best to contact them. We went to the Lichfield and District show. Got there at 10.30 to be told no public until 12.30, after judging. Couldn't wait around outside the hall for two hours so went back home.
They might have birds for sale, but the small shows we have been to were all free entry and had nothing at all there but the birds on show.
Best show is the Federation at Stafford showground in December. Thousands of entries, plus birds for sale and trade stands -£8 each to get in. The National is at Stonleigh a few weeks earlier, has less birds but more trade stands and cheaper beverages - but £16 each I think we paid! Both have entries from the whole Country.