When it comes to how long to practice, that is a great question! These days I like to play for about 1/2 hour at a time, several times a day.
When I was growing up, I would practice for at least 1 hour. In 1963 I had a good deal of time to play and spent ten hours a day doing so. I was getting ready for an audition at UC Berkeley, to get into the Masters Class with Andres Segovia. What I realized was that after two hours of playing, I could play anything I wanted, play it well, and felt so free!
There was a small "wood spider", that would come out while I played guitar. It would move about two inches from under the wall trim and stay in front of me, and if I stopped playing it would return to the area beneath the wall trim. As soon as I continued to play, the little spider would come out again. It is nice to have an appreciative audience!
These days my wife is my audience, and she has always enjoyed the music I play. She is a good singer, and sings many different types of songs.
Tom