Hi!
If you're a complete beginner, then you should take lessons with a profi - they could direct you at the beginning of your way. Once you get some basis, you can move forward on your own or with a guide. At the same time a teacher is a factor that makes you not give up. Without a teacher you may lose your way in the world of Russian, the information would pile up and one day you'd feel completely lost. To immerse in the Russian-speaking world, it's good to listen to the radio and songs (reading lyrics in parallel), to read Russian-speaking blogs to your interest...