Small piece of advice: When you're in career and you decide to do an optional race on a turn (because you need skill points or the other options aren't good), make sure to look at your options and fish for an appropriate green skills if possible. Winning races has a chance of giving you an associated green skills, so if you pick a race with some conditions matching the CM conditions you're training for, you might get a free green skill (e.g. a 1800m optional race has a chance to give you a Non-Standard Distance hint).
The list of things you can get is long, there's orientation (i.e. left-/right-handed), (non-)standard distance, season, weather, firm/wet, and also less useful stuff like inner/outer post proficiency, comp. spirit, target in sight.