Different races, different priorities
Each race or event carries a type, date, distance, and a priority: A, B, or C. An A-race is the goal the whole plan is really built around, the one you peak for with a full taper and your best form on the day.
A B-race matters too, often a proper tune-up or a step on the way to the A-race, but usually gets a shorter taper so it doesn't eat into the training block around it.
A C-race is lower-stakes still, more of a fitness check or a chance to practice race-day logistics, and typically needs little more than backing off the days before.
You can add events for each athlete from their profile page, under the Season tab. Click Add event and fill in the Add race or event dialog: the event type, its priority, its date, and its distance where the type doesn't already imply one.
Or simply tell your AI co-pilot to add it for you. Either way it appears on the season timeline straight away (see Reading the season view).
Multiple races combined
A single plan can hold multiple events at once, and their priorities are what shape how its phases get laid out. One A-race gives you one clear build-and-taper block to plan around. Several A-races across a season mean multiple build-and-taper blocks in sequence, each with its own peak. B and C races slot in between without disrupting that structure too much.
From the Season tab you can only add events. When one moves, or the athlete pulls out of it, ask your co-pilot to change or remove it: it reshapes the phases around the event as it goes, which is the part you would otherwise have to redo by hand.
Not every plan needs a race. An athlete training for ongoing development can have a plan with no events at all. See Creating and adjusting a training plan for the different ways to start one.