Requirements differ from bank to bank, but usually you’ll need to have a residential address and some identification. If you’re applying online you’ll need to provide your information to the bank you’re applying with.
You’ll need a bank account for things like having your salary paid and in order to make direct debit payments like paying for bills such as your mobile phone contract, water and electricity, etc.
There are plenty of free bank accounts available with various different banks, but there are also fee charging bank accounts too. It’s best to make sure you check when applying for a new bank account.