Hello there, Ink~
Now, tilesets aren't all too tricky. I'll upload my blank one~
The tiles on the top of that .flow chipset are water tiles. they don't actually have to be water, but they are the default layer one tile, and they animate. I would reccomend looking at the RPGmaker default tilesets to see how to do those.
The ones with the big squares on the lefthand side are special tiles. instead of being one tile that repeats over and over, these ones are dynamic. Again, I will refer you to the defaults to see how they work, they are simple~
the tiles on the left hand side that are yellow and green are animated tiles. they animated up and down, from top to bottom.
The tiles in the middle are normal tiles.
Now, on your image, anything to the right of that yellow line is a layer 2 tile. you seem like you already know what they are.
Normal events on the map can look like that maps current layer 2 tiles. If a layer 2 tile looks like it is doing something wierd in an rpg maker game, it might just be an event that has some events that make it flash
Misc Stuff about tile sets:
Like everything else, it has to be a 256 color PNG
when using dynamic tiles, hold shift to place them like normal tiles
I'll help you more if you have more specific questions or I think of anything else.