You may not be able to get everything you want. The justice system is not perfect. There may be delays and disappointments. Every legal problem is different, so we cannot tell you here how much it will cost you to hire a lawyer. You and your lawyer need to talk about fees the first time you meet.
Lawyers have different ways of calculating their fees.
They may charge a fixed fee for doing a specific task, like writing a will. Or, they may set their fees according to the amount of money or value of the property involved in your case. Real estate lawyers, for example, often charge you a percent of the value of the house you are buying or selling. In other cases, lawyers will keep track of all the time they spend working for you and charge you for it, using an hourly rate. Your lawyer's hourly rate may change if there is an emergency or if your case goes to court.