For Bitcoin and transactions using a bank card you will need to provide both Proof of Identity (POI) and Proof of Residence (POR), but for almost every other payment method this is not necessary at first.
You will need to fully verify your Personal Area eventually if you wish to continue trading.
To fully verify your Personal Area, log in and click Verify Profile at the top of the main area. Follow the on-screen prompts to upload your POI and POR documents, and once confirmed you will be able to transact with any available payment methods (regional limits still apply).
For more information, read our comprehensive guide to payments.