Do you get paid for onboarding?

Yes, you get paid for onboarding. Job training is an essential part of the job, and all the time you spend on onboarding tasks should be paid. Under FLSA guidelines, the only onboarding tasks that are allowed to not be paid must meet all four of the following criteria: the event is outside business hours, you can choose not to go, it is not work-related, and no work is being completed.

Basically, if it's an optional after-work social event and everyone is "off-the-clock," then you are too. But regular onboarding tasks that you perform during normal work hours alongside your colleagues are simply part of the job you've been hired for.