Listen to radio and songs, watch movies english to russian, series, news in German. Even if you do not understand anything, this will help you get used to the sound of German speech, to feel the characteristic features of the intonation of German speech. For the German language, the most important moment of intonation is not melody, but a special rhythm that sharply distinguishes German speech from Russian or English.
Even if you study from self-study books, make a schedule of lessons and practice regularly. As practice shows, it is better to spend 20-30 minutes studying a language every day than 5-6 hours once a week. Irregular classes will not bring benefits. Be sure to draw up a program for yourself (you can find examples on the Internet and adapt to yourself), write down dates and milestones to evaluate progress. When choosing the intensity of classes, consider your busyness, but in any case, it is better to start learning German at a measured pace.
Make the process of learning German and english to french as comfortable, interesting and exciting as possible. If classes are fun, it stimulates the brain to create associative links with incoming information.
Pronunciation is an important part of learning German. You need to use the right pronunciation tools from the very beginning. These can be manuals on the phonetics of the German language, special podcasts by German authors, etc. Yes, it is very difficult to put the correct pronunciation on your own, therefore, at the first stages, feedback from a mentor is required.