Regardless of the style of music you sing, It is important to have a correct approach to practice. You will benefit more from several short practices (e.g., 20-30 minutes per day) than one or two long sessions per week.
This is especially so in the early stages, because your muscles and your voice are still developing. If you want to become a great singer you will obviously have to practice more as time goes on, but it is still better to work on new things a bit at a time. Take one small piece of information and learn it well before going on to the next topic. Make sure each new technique is thoroughly worked into your singing. This way you won’t forget it, and you can build on everything you learn.
In a practice session you should divide your time evenly between the study of new material and the revision of past work. It is a common mistake for semi-advanced students to practice only the songs they can already sing well. Although this is enjoyable, it is not a satisfactory method of practice. You should also try to correct mistakes and experiment with new ideas. To develop good timing, it is essential that you always practice with a metronome (or drum machine). Beginning singers are often particularly weak in this area. Your timing and all-round musicianship will also improve dramatically if you learn to accompany yourself on keyboard or guitar.
Apart from practicing your actual singing technique, it is important to spend time thinking about the lyrics of each song and how you can bring meaning to the song with your interpretation. From this point of view it is useful to learn a bit about acting. Maybe you could talk to an actor or take a few drama lessons.