Your ability to keep your property(personal and real) depends on the exemptions you qualify for. Most people can keep their homes, cars, and normal household belongings. Please consult an attorney to learn more about what would be exempt.
Yes, your bankruptcy filing will stop any lawsuit that is currently in progress. If you have a judgment against you, the debt owed from the judgment will be discharged. Please consult an attorney on whether there are any extra steps needed to remove judgment liens.
Examples of secured debts include homes and vehicles. They have liens against them that must be paid in full before title/deed can be passed to the owner. Unsecured debts are not encumbered by any liens. Credit card debt is the biggest example.