Animal Companion and Mount

[supermercado08]

So it states an ally can use your animal companion as a mount, if you do then who is using the actions to control it? And during whose turn does it go? If the rider is using their action to control it is it still considered a minion for them?

Also in regards to when companions act (not mounted in this question) can you split up the actions? Such as You use your stride action to move into range, you command it to stride into a flanking position, then you attack and then it attacks or must you use your 3 then it's 2?

[Themetricsystem]

In order to have you animal companion or familiar take ANY actions you must spend 1 Action to Command them > They get 2 Actions they know the Trick for (Or if they're intelligent anything they can understand)

So you spend 1 of your Actions every turn you are riding the Mount to Command the Mount, and you then have 2 personal Actions left and the Companion gets 2 Actions.

You're fighting beside (Not Mounted) your Cat/Bear/Horse/Whatever - You Stride to Move into threatening Range of Enemy > You Command the Animal > The Animal takes 2 Actions (Stride & Strike a Flanked Creature) > You use the Strike Action

They act on your Initiative, and they take ALL of their actions at the time when you Command them (As part of your Command Action they begin their actions) and then when they are done you resume "your" turn.