Just wondering,can anyone/group give themselves a fancy name,call themselves a charitable organisation and put on events etc without any checks/registration in the UK ?
Anyone can give themselves a fancy name, provided they are not committing fraud or impersonating another organisation. Anyone can put on events, but they have to disclose what it's about and pay tax on the profits (how it's taxed depends on the type of organisation). Many types of event need a licence.
You can only call yourself a charitable organisation if you are. That means you need to be a non-profit making organisation and any income you receive, net of expenses, has to be used for charitable purposes. You can only call yourself a registered charity if you are. That means you are registered with the charity commission and produce annual accounts to the standards they require.