I could translate...
"MIS" is just the name of the store
under that it says "Simple hospitality services and small trades"
"vl. " stands for " vlasnik" which means "owner of the business", and the owner's name is written there but I can't really read it. The last line is the address of the business.
I am from Serbia so I am not 100% sure about this coupon, but I think that this type of coupons are given to employees by their employer "Robni Magazin" as some form of benefits. The value of it was 500 dinars and the holder of the coupon could spend it in many different stores. I am assuming that this particular coupon was used in the store called "Mis" and that's why there is the "Mis" stamp on the back of it.
Also, keep in mind that this coupon is from 1982 and Croatia was part of Yugoslavia back than. Even though this coupon was issued and used in Zagreb which today is capital of Croatia, I would still call it Yugoslavian and not Croatian.