Any song or other music composed and published in the 1830s is very likely to be in the public domain by now, although it will depend on the exact laws in your country, and, in some countries, on the year in which the author/composer died. In the US if it was published before 1924 it will be in the public domain now, but the rule is different in different countries.
Assuming that the work is in the public domain, you may freely create translations, or modified versions, and perform them. You may sell those performances, or distribute them free of charge.
In all countries which adhere to the Berne Copyright Convention, which meals all but a handful of countries in the world, your work is fully protected the moment you write4 it down, or otherwise "fix it in a tangible medium". (Computer files count.)
In the US you may choose to register a copyright. This gives you additional rights should you sue for infringement later. It also provides evidence of your copyrighted work. However, there is a fee. Some other countries have similar procedures. Each country is different, and registration in one does not provide registration in any other. But in all of the Berne countries, registration is optional.
