Trains are gained once every 4 levels on Solace.
You can train stats at any trainer, with 1 training session being able to
raise any one primary stat (str, int, wis, dex, con) by 1 point up to your
racial maximum.
Training hit points and mana is a little different.
On Solace classes gain different benefits from training these depending on
their aptitude for the particular training type. Fighters gain better from
hit point training than mages, and so on.
The amount of hp or mana you gain is slightly random with each training
session you use.
ADVICE: If you want to live longer train con to max first.