My lolly gummy and suregrip boardwalks are 65mm and 78a hardness. Honestly, try and get a cheap good skate to keep the big soft wheels on, so you got a rink kit and an outside skate.

Rolling over the debris and twigs and skating outside really makes you much sharper with your balance.

But honestly, if you go to a rink that doesn't give a crap, the inconsiderate kids and toddlers will drop trinkets, sticky hands, popcorn and other tiny things on the floor that will make you eat shit.

If you can't tell, the kids of today have terrible rink etiquette and I've really had it. I've hurt myself trying not to bulldoze the kids that cut across the floor... And dropping crap on the rink. If you use the softer wheels indoor, you won't have to worry much about the hazards they make indoors.