Welcome to the forum.
One option for getting a mortgage is to go into several banks and savings banks (cajas) local to the area you are buying in and see what they have to offer. Always negotiate, and always get whatever they do offer in writing, so they can’t hit you with surprise charges in the Notary’s office.
Alternatively, if you want a good broker to study your case, advise you how much you can borrow, under what terms, and help you get the best deal on the market then fill in this mortgage enquiry form and I’ll pass it onto a good broker who charges very reasonably (0.5% success fee – can anyone beat that?) and nothing upfront.
I don’t know of any lawyers in Nerja (I’m on the lookout for a good one), but one of the Marbella-based lawyers on this list might be able to help you. All the lawyers on the list are great professionals who look after their clients’ interests (and nobody else’s).