How will I choose the right bankruptcy chapter?

Yes, you have to seek help from a lawyer. The bankruptcy is complicated subject.

No. It doesn't work like that. You have to consult the lawyer, explain your entire financial situation, and submit all the papers. The lawyer will tell you which chapter of bankruptcy is suitable for you. If you have too many non-exempt assets, then probably he will recommend Chapter 7 bankruptcy to you. It's not mandatory to get help from a lawyer. But it's better to consult a lawyer since the bankruptcy rules are quite complex.

It will depend on your financial situation, your assets, liabilities, and your affordability. Your attorney will suggest you which chapter of bankruptcy is best for you. It's not mandatory to get help from an attorney, but it might be beneficial if you do so.