There’s no problem as long as the song gives you a vibe and sense of happiness and peace cause both of those things are calming to people but what ever you do don’t listen to sad and/or angry music because that’s not the type of energy you would want to put into your mind nor atmosphere.
Yes and no. You want to make sure your music isn't something that will make you move and groove, but something that will soothe and ease your mind to stay focused. Having just a beat or soothing sound can help ease into connections with your inner self. Try nature sounds or bells first. Too many sounds can become a distraction, especially for beginners.
There’s no wrong way to have your environment for meditation. Music is acceptable, but maybe pick something without lyrics and play it very softly in the background. And you might want to look into the meditation that has you actively listening to ambient noises around you and then letting them go without judgment or identification.
That depends on the person and the music. Calming sounds with piano music can make it easier for some people to meditate, while others need complete silence. Try different music styles while meditating and findwhat is good for you.