Lucid Dreaming comes hand in hand with Dream Recall. Lucid dreaming occurs when you are dreaming and you come upon the realization that you are dreaming and are able to control it. Astral Projection is a personal and out of body experience. It is when your physical body is in a restful sleep-like state but you are consciously awake. It is in this state when you can astral project with your "astral body". To avoid confusion with the concepts of soul/spirit, that is what it is commonly called.
Before practicing either Astral Projection or Lucid Dreaming, you need to practice Dream Recall.
You need to constantly tell yourself as you're falling asleep ''I will remember my dreams and I will control them'' or something along those lines. Keep a journal next to you. Wrote down what you remember the next morning. This tells your subconscious how important this is for you, and soon, you will remember your dreams and be able to control them as well. Do reality checks every day and ask yourself "Am I dreaming?" Pay close attention to your surroundings. Once you develop this habit, the next time you dream, you may ask yourself the same question, perform a reality check, and realize that you are indeed dreaming.
After you accomplish this, it will become easier to astral project. It may take a while, but it's worth it if it will increase the success rate of your astral projecting. The thing is, sometimes, we do astral project and then forget about it. This way, you will learn to remember if you did astral project.