How to support a toddler to toilet
Toddlers can usually sit happily by themselves, but it pays to stay close in case they fall off the potty by accident. Having you close also gives them the reassurance that they're safe and can help them relax into letting go of their pee or poo. Toddlers can be very fussy where they want to go to the toilet (after you define several locations that you deem appropriate it can be helpful to let them have some power to choose) and if pays to mix it up sometimes for some kids to re-engage them in the process.
Ideally, have your toddler sit in a deep squat to help their body release (this puts gentle pressure on the bladder and straightens up the colon). Another benefit of the squat is that often very little wiping/cleaning up is needed.