You should consider what you want to achieve and the information you have available.

The more preparation you do before the meeting, the more beneficial it will be.  It is worth making a list of the main points you want to discuss or the questions you want to ask.  Obtain any relevant paperwork and put it in some kind of order so that you can refer to it quickly.  This will make it quicker and easier for your solicitor to understand your circumstances and give you proper advice.