The park I skate most is circular so a lot of young scoot kids will just loop endlessly without pause.
If they're really young, I'll go up nicely and say "Hey I'm just in this one spot can you stay on the other side of the park so I don't run into you?" Or some other way to make them see that there's etiquette to being at the park.
If that fails, I usually shout watch out when they get close but not in an overtly mean way.
If that fails, I'll just do my thing without regarding them.
There have been times where I've had to confront parents. Telling them, look I've been standing here patiently while your kid has been zipping around for the last 10 minutes non-stop. It usually does the trick. However, there have been times when parents get confrontational over it. Coach dads and tiger moms have tunnel vision when their kid is involved so that's when I bust out the speakerbox and play some shitty music on it. Most of the time though, the younger crowd will take care of the little guys before I have to get involved.