I drink coffee just for the flavor, the caffeine doesn't really do anything for me unless I have a ton of it.
There's really no consistency in how I drink it, just depends on what I'm in the mood for. I'll sometimes drink it completely black if it's cold brew (heated before drinking) made with good beans, but otherwise I'll always add something, maybe cream, maybe sugar or another sweetener, maybe both. Spiced coffee is good too, cinnamon, cloves, cardamom, nutmeg, etc.
Cold brew is what I prefer but I rarely bother to make it, pour over is my usual method if I'm making it myself, or if someone else makes it then it's probably just brewed in a cheap coffee maker.
I got myself a nice conical burr grinder a while back to freshly grind my own beans, but honestly I don't make enough use of it to justify the cost, and it's a bit of a waste if I don't spend even more on high-quality beans.
Coffee can add some nice flavor to other things too, especially smoothies. Coffee flavor goes really well with bananas and oranges. I just add a bit of freshly ground beans or even cheap instant coffee to the blender. Coffee shakes on their own are pretty good too.
I don't remember when I started drinking coffee, I've liked it ever since I was a kid. I've gotten more into it in the past couple years though, being influenced by my previous girlfriend who is somewhat obsessed with coffee.