In regards to being a beginner with deep breathing, visualizing, and meditation, I can definitely relate to you. Even though I'm just starting, I try to remember "No matter how short my meditation lasts, the fact that I did any amount of time is a success".

Deep breathing is pretty much self-explanatory. The issue is remembering to do it when the need arises. Like you, I usually only do the deep breathing when I'm calm. I suppose this takes practice.

Visualizing is a bit more complicated. For me, when I visualize a beach, yes, I do see a beach. The picture is not perfect because it's generated from my brain and not real, but the picture is there nonetheless. Maybe if you can't actually see the beach, it still may be beneficial to think about how it would feel to be on the beach...how the sand would feel warm under your feet, a refreshing breeze, etc. If you enjoy drawing, maybe you could draw a beach or another nature scene?

Meditation...that is the one I'm focusing on right now. What's helping me is I look for free videos online of meditation sounds (I meditate better with calming sounds than with silence) and I sit cross-legged with my hands face down on my thighs. I breathe in and out slowly and calmly, either thinking of nothing...or if a thought does come into my mind...I try to let it flow by like a river. Sometimes it's difficult though, because I can get some thoughts that worry me and get stuck on those! At the moment, I can achieve about 10 minutes of meditation a day, and I'm hoping that number grows as I continue to practice.

Of course, you'll have to figure out what works best for you. I'm sure after trying out different things, you'll find some great techniques for deep breathing, visualizing, and meditating. Best of luck to you!