Bankruptcy is a way of being released from debts that you can't pay. It is a legal proceeding, and once you are declared bankrupt, it is illegal to pay any of your creditors.
Your case will be taken on by an official receiver, who will examine your circumstances, and your income, and decide if you have any surplus income. In this case, you would be expected to contribute to your bankruptcy for 3 years. If you have little or no surplus, you would not have to pay anything.
You are bankrupt for a year, and get discharged automatically after this. But, if you have been extremely reckless (not just a little irresponsible or buried head in sand) you can be given a Bankruptcy Restrictions Order for up to 15 years, which restricts you to the conditions of bankruptcy.
You will only be able to operate a basic bank account, but to be honest, most people contemplating a move like this have a terrible credit score anyway.
The main thing is to consider whether your current circumstances, without your debts, will support you. There is no point filing bankruptcy if you are headed straight back into debt. It needs to be a final step to get back in the black.
You will also need to be able to pay the costs of filing bankruptcy, which are £485 unless you are on benefits, or earn under £14600, in which case that is reduced to £335.