how do you learn mechanics?

[Rongway]

Besides looking at the mechanics telegraphs and where people are going, also look at the arena floor. Many trials and raids have floor designs that are meant to help you know where safe spots are if you know how to read them.

For example, if the floor is made of tiles or bricks and there happens to be one particular tile in each of the cardinal directions that is a different color, there is an incredibly high probability that the devs expect you to handle a mechanic by having people stand on the conspicuous tiles. Maybe the distance between two tiles marks the safe distance for a knockback/drawin mechanic, or the minimum dance from the edge of the arena where you can stand without getting yote. Maybe four people are going to get hit by an AoE and the tiles mark the minimum safe distance that the four people can stand from each other without killing each other.

If there are grooves in the floor that look like large circles in a flower pattern, chances are at some point there will be circular AoEs emanating from the center of each circle, and the circles on the floor show you how big the AoEs will be so you can stand outside of them. There might be six circles and five of them will blow up so you need to stand in the section of the floor that is in the safe circle but outside the overlapping circles to the left and right.

If the floor has some intricate design that repeats after 120º, dividing the arena into thirds or sixths, there will probably be some mechanic that has safe spots every 120º or 60º. This type of floor sometimes hints at something like three line AoEs going across the arena, and the safe spots between the lines are marked by some part of the floor decoration.

Knowing that the arena floors are drawn this way and thinking about what different recurring floor geometries are trying to tell you might give you enough extra information to figure out how to handle a mechanic that killed you.