Upvote:1
As far as documents to bring with you goes, the official advice is to carry with you the same documents you’d use to apply for a visa to show to Immigration if asked. This would include for example, documents to prove:
During the landing interview the Immigration Officer may ask whether you have family in the UK. You must tell the truth, if asked, see V9 https://www.gov.uk/guidance/immigration-rules/immigration-rules-appendix-v-visitor-rules and related question UK visa refused, now I want to reapply but didn't mention my family last time - what to do?