Lucid dreaming is usually a sign of good concentration but I would assume nothing at first. Scripting your self into "dark night" territory and attaching truth to that could hinder you right at the beginning. The way I started was developing jhanas and by the 2nd jhana I moved onto insight. The best thing I can tell you is to make your practice as practical as possible in daily life so that practice helps daily life and you get more hours of practice without disengaging from life and responsiblities (unless you have time for retreats). With trial and error you can see how the practice can help you make skillful choices.
Try and pay attention to the breath with continuity during the day. When you do higher processing work you won't be able to but when there are gaps in that thinking you can go back to it. It's fun to just focus on what needs to be done and block out thoughts related to likes and dislikes to relieve the usual craving and aversion people have. Being in a busy environment and staying present with your breath or task will send you in the right direction. I would also look into the jhana factors which show how the process develops. It's like inertia in that you have to get the ball rolling with effort before proper effect takes place.
Jhana Factor
1. Applied Thought Eliminates Drowsiness and laziness
2. Sustained thought Eliminates Doubt,
3. Joy or Rapture Eliminates Ill Will,
4. Peaceful Happiness Eliminates Restlessness
5. One-pointed Concentration Eliminates Sensual Desire.
So if you keep at it in your practice over months you should be able to develop enough skill to see the above results. When you get good at this practice you'll notice that paying attention to something and sticking to it prevents the brain from obsessive thoughts over likes and dislikes so a nice satisfaction pervades you. Unfortunately you have to block thoughts if you want to absorb completely in your object so you'll find limits. This is why thoughts have to be let in eventually and then you should practice insight with the concentration you developed.
One thing I enjoyed doing at first was noting practice while walking on nice days. I also enjoyed noting while driving. Noting seems to make chores less of a chore and thoughts can be an object of contemplation. A similar tack on the jhana factors are the factors for awakening which can use concentration as a foundation for investigation of your phenomenological experience.
1. Note with mindfulness which supports the next factors.
2. Investigate 3 characteristics of the 5 aggregates which eliminates doubt about the practice which increases the capacity for...
3. Energy to eliminate sloth and torpor which creates..
4. Joy which eliminates restlessness and worry which improves your...
5. Concentration which overtime helps you develop...
6. Equanimity
Of course all this stuff requires more reading including Daniel's Mastering the Core Teachings of the Buddha. The books and websites section of this site has lots of good suggestions. I would also look at this thread from Ian And especially:
Essential Books From Theravadin ResourcesHopefully that is a good direction for you to start.