Legal advice is usually sold by the hour, and the first hour is the one most people waste. They arrive with a story but no paperwork, tell it out of order, and leave having spent the time on things a folder of documents would have covered in ten minutes.
Start with identification. Solicitors must verify who you are before they can act, so a passport or driving licence and proof of address save a follow-up visit. Then the papers: the contract, the tenancy agreement, the letters, the emails, whatever the dispute or transaction lives in, arranged in date order. Add a one-page timeline you wrote yourself, with dates, because a solicitor reading a clean timeline absorbs your situation faster than one listening to it. Bring the full names of everyone involved too. Firms have to check for conflicts of interest before taking you on, and they cannot do that from first names.
Not winning the case. The first meeting establishes scope: what you want, whether the solicitor thinks it is achievable, what the steps look like and roughly what they cost. Expect to be asked hard questions about weaknesses in your position. That is the service working, not the solicitor doubting you.
Money should come up early and unprompted. Solicitors are expected to give their best costs information at the outset, so the meeting should cover how the firm charges for your kind of matter, whether that is an hourly rate, a fixed fee, or for some injury claims a conditional fee agreement, and what the estimate looks like in writing. If you are hoping for legal aid, ask directly; its scope is narrow these days, and a firm that does legal aid work will say so quickly. If money has not been mentioned by the time you stand up, mention it yourself and watch how the question lands.
Promise you the outcome. General guidance on merits, yes. A view on your prospects, often. A guarantee that you will win, never, and a lawyer who offers one in the first hour is telling you something about themselves rather than about your case. Treat confident certainty as a reason to get a second opinion, not a reason to sign.
Ask who will do the day-to-day work on your file, since it is often not the person in the meeting, and ask for that person's name. Ask what the next step is and when you will hear about it. Ask what would make the solicitor advise you to stop, because knowing the exit before you enter is worth a great deal. And ask for the firm's complaints procedure; every regulated firm has one, complaints go to the firm first and then to the Legal Ombudsman, and a firm that hands the leaflet over without flinching is a firm used to being accountable.
If you have not chosen a firm yet, this site lists 2,926 solicitors' firms with their practice areas and locations. Browse firms near you, or set out your matter once and let firms respond with quotes. Then, tonight, write the timeline. It is one page of work and it is the cheapest legal preparation you will ever do.