For my "career" as a guard, there's levels of "Do I help this person?"
Crying young child in rental skates: Yes, do help.
Crying older child in rental skates: Go over, ask if okay, offer hand.
Crying child under 5 in figure skates: Go over, ask if okay, offer hand. Child may refuse.
Crying child in hockey skates: Look for crazed hockey dad either in stands or on ice. Go over, ask if okay, offer hand. Child may take it but if crazed hockey dad is nearby, be prepared to be shoo'd away.
Crying child over 5 in figure skates, observed doing skating practice: Watch from afar for a moment to see if they get up. If no, go over and ask if okay. If yes, they're fine.
Crying teen in figure skates, observed doing skating practice: Suck it up, buttercup.
Crying teen in hockey skates: Never happens.
Adult who took a hard fall and is laughing: Go over, ask if okay, offer hand.
Adult who took a hard fall and lies there: Go over, get down on the ice, ask if okay. Take further first aid from there if needed. Usually it's not, they're just a bit stunned.
Large adult, chronically falling and flailing: Go over, tell them to take it easy and/or hold the wall. Be advised that if you try to help this person up from a fall, they will pull up on you and threaten to pull you down. Brace yourself. I always get a little nervous helping up someone twice my size, but I've not been dragged down yet.
And with any fall, keep an eye on that person for awhile. Sometimes people think they're okay when they're not!
You'll retie more skates than you ever imagined, simply because people wander onto the ice with their ankles literally flopping around in their boots. Not helping them is a safety concern. (And all of them will complain that you tied it too tight... LOL)
And as for people asking me to help their child learn to skate, I just advise that they hold onto the wall until they get comfortable.