Financial advice is heavily regulated to help keep you and your money safe and provide compensation if things go wrong. Therefore, to get proper advice that is personally tailored to your specific needs and circumstances, you should expect to pay a fee.
That is not to say that the best advice is delivered by the most expensive advisers..... the overheads for each firm will vary and asking for local recommendations of IFAs that others have been happy with would be a good starting point.
A good adviser will take a holistic view of your financial planning, so a general adviser would do fine to start with. They can contact specialists if necessary, depending what you're trying to achieve.
It is only regulated advisers who can make product recommendations, such as for a new mortgage.
You may see people advertising themselves as "financial planners". They may not be regulated and, if not, they are limited in what they are legally allowed to do. They will charge fees. You will not be covered by any recourse to the Financial Services Compensation Scheme or Financial Ombudsman.
There is lots of financial "guidance" freely available from many sources, including for example Money Saving Expert, MN users and the bloke down the pub. But they also cannot legally give advice and you cannot sue them if things go wrong as a result of doing what they say.