If you want to change your name for any reason there are various options available to you. In the UK, you can of course, simply adopt your chosen name and there is no obligation on you to do anything more than that. However, if you wish to change your name on your passport, bank account, driving licence etc. you will need formal documents recording the change (where your surname changes on marriage you can of course simply produce your marriage certificate to evidence the change).
A Notary Public can draft the necessary legal document to record the change of name but it is important to be aware that there are several options available to you – including solicitors and online services. The important point to note is that charges for the service can vary enormously and so a little research may help you to identify the most cost effective option for you, taking into account the number of original/certified copies you may require.
Remember also that once you are in possession of the legal document recording the change (which may or may not bear a Notarial seal)! that it will mean nothing unless you actually start using your new name!