Here is a practical guide for beginners. This is a concise description, for the purpose of introducing a subject that is really a life long study. I am omitting many details, because I think that, sometimes, the introuduction to the basics of magick can be somewhat overwhelming for a beginner. More advanced practioners don't need this thread. It is specifically an introduction for those setting out.
So, everyone is telling you to meditate. In order to meditate, we need to relax. Both of these are helped enormously by Breathing. To relax, get comfy. Become Aware of your breathing. Don't try to change it, just become aware of it. The more you are aware of your breathing, the less you are aware of the chatter of your thoughts. Notice the sound, the feeling, and the movement, of your breath. The thoughts will get quieter and quieter, until you are no longer aware of them. You will be immersed in your breathing, - your being. So, you see, we don't have to try to stop our thoughts. By being increasingly aware of our breathing, the chatter stops by itself.
When you are relaxed, your head space is free for your creation. That is your meditation. You have made a clean canvas for your work. For starting out, remember a place in your life, that is peaceful and calming to you.
Now we visualise it. So, the meditation and visualisation go hand in hand. You are painting your canvas. Visualisation encompasses all the senses. What can you see? What can you hear? What can you smell, taste and feel? The more sensory angles you use, the more powerful your visualisation. We practice this skill so that we an create whatever we like in our minds, for intrinsic purposes, or for the purpose of spell craft.
Now, we have command of our minds. So, we can familiarise ourselves with what energy feels like. We all have energy already. We are all alive! It is just a matter of becoming aware of it. Most people start out by Feeling energy. I do. I recommend trying this with a friend. Both of you, shake your arms, hands and fingers out vigorously. Sit cross legged in front of each other. Place the palms of your hands almost against each other's, and focus on what you can feel in the space between your hands. What you can feel is ENERGY. This is what we work with in magick.
The rest is basically learning to be in command of this energy. There is much, much more detail to it than that which I'm writing here. This is what magick practice is about. The energy you felt in the exercise, is pulsating in your whole body, and more. Now you know what it feels like, you know how to look for that feeling in other parts of your body. This is what you can explore in meditation. You can feel it swelling around your body.
"Centering", is focusing it in one place, like your tummy. We do this by focus and will. You will get the hang of it. Look for lessons on this when you are ready.
"Grounding", is moving your energy from that place, as the starting point, and connecting yourself deep into the energy of the earth. We do this by focusing on, and manipulating by will, the energy that we can feel. We can use visualisation to help us. Whether it is your energy, or earth energy, or your pet's energy, it is all the same energy. So you see, life is energy. Magick is enjoying how all is related by the same cosmic 'glue' (as I like to call it).
More lessons on 'The Basics' teach you how to utilise this energy. I suggest you spend a lot of time reading and practicing. Never be afraid to ask questions, and I wish you well on your path! :D