Where should I start with the initial D anime series? Chrono?

The first series...

The first one.
Also avoid the dubs, especially the first one which took all the eurobeat and replaced it with trash, americanized all the names, and flopped all the street scenes in order to make all the cars drive on the RIGHT side of the road.

>>161131375
The first season is really all you should ever watch, 2nd and 3rd if you want more, 4 to end is if you want to watch something you loved be shat on.