Dude! I know what you are feeling! For me, it was 1970. I had no idea what to do! Literally! I was just hanging out there with absolutlely no idea! That was what I hated most, that I was hanging out there with absolutely no idea what I was supposed to do! I won't even get into the next 20-odd years of misinformation I was given.
For one thing, most of us here on dance-forums have trained for our dances. "Grinding" and what-not are foreign terms to us. We're into partner dances, where the guy leads and the girl follows. Since you're talking about grinding and what-not, we're out of our depths.
You are way ahead of where I was back in the 60's/70's. Think for a moment about your music. It's 8-count, isn't it? So is hip-hop (I've sat in watching enough hip-hop classes to know that hip-hop is 8-count). Is the music you're going to dance to also 8-count? I'd be extremely surprised to learn that it is not!
OK, let's get hep with the jive, gator! Dance music is 8-count. It was true in the 1930's and 1940's and ever since then. There's a one, and it counts through to eight. I've seen it back then and I see it now. Eight Counts. Listen for it! Follow it! Believe me. I've also done ballroom, and even their music (whether their teachers want to acknowledge it or not) has a ONE -- FWIW, if you ever really want to learn about the phrasing of music, you will need to tap into the original jive ... swing)).
Listen to the One. Listen to your music. Count the beats. Listen for where the beats start. Believe me, it's there! Usually, the lyrics will start on a One. The instrumentals will start on a One. Listen. You will hear it.
My friend takes a different approach. She listens for the "Seven, Eight". I didn't believe it, but I finally saw that, for swing music at least, the band does indeed put more emphasis on "7, 8" so that we can hear the "one, two" better.
Joke: How many dancers does it take to screw in a light bulb? "5, 6, 7, 8."
OK, now here's the real secret.
Who are you dancing with?
At the beginning of the song, there's an intro. Synchronize with your dance partner during that intro. The end of the intro is the One -- actually, it's the Eight right before the One -- which is the beginning of the dance. That's when the dance begins.
No matter how "right" you are about where the "One" is, that never ever matters. Do you see that "frail" in front of you -- Guy, I mean that female, that one feminine person who makes this entire dance evolution important (sorry, I'm Navy)! As you synchronize your dance, sycn it up with her! Why are you even dancing? It's because of her! I don't care whether you're dancing Lindy or who knows what. Sync up with her. Then dance with her. That's all she wrote!