questions from a first time apple watch user

I just got my first apple watch a few days ago, tons better than my old fitbit that I was using. I do have a few questions. First, after ending a phone call, I noticed the watch's volume goes from 40 percent back up to 60 percent, which is way to loud for me. How can I keep my watch at 40 percent after ending a phone call or dictating a text message? Second, how do you get the mindfulness app to work? I logged my mood last night and again this morning. When I checked the mindfulness app, I couldn't find anything indicating where I logged my mood. Third, is there any way you can turn off the voiceover sounds, but still leave the other watch sounds on? Lastly, what apps do you all use on your apple watches? What do you like or dislike about them?