Welcome to Dreamviews!

You don't have to worry about newbie bashing here, everyone's really nice. Here are some answers:

-details depend on how vivid your dream is. There are techniques to increase vividness within lucid dreams, but it's quite like any other dream in terms of vividness. Another factor in how vivid it is is what technique you are using to become lucid; although I've only ever done DILD (Dream Induced Lucid Dreams)

-if you've never done it before, it feels like you think it should feel. The first time I drank coffee it was in a lucid dream, and it tasted exactly as I thought and wanted it to taste; when I later tried it in real life it was completely different.

-I don't really think that playing an instrument in a dream can help in real life, as you aren't concentrating on it as much. In a dream you could instantly make yourself amazing at the instrument and you wouldn't need practice (or you could make the right sounds with the wrong notes). It's always better to practice things in real life.

For further answers, try looking in the tutorials section; it has tons of helpful stuff. And don't be afraid to ask questions!

Hope to see you around!