I've been to the united states for 3 months and made an overstay for 1 month. and now i want to apply for a uk visa, but I've heard about sharing info between countries ? would that affect me in the future, or it's easy to renew my passport and dont mention my previous us trip ?
The UK and USA do share information Do the governments of United Kingdom and USA share immigration data? You will have to declare the overstay in your UK visa application or you risk an automatic refusal under Paragraph 320(7A) of the Immigration Rules https://www.gov.uk/guidance/immigration-rules/immigration-rules-part-9-grounds-for-refusal if they find out about it, and a 10 year ban for deception.