As I arrived, the desk assigned me a parking spot. There is not much parking... Sorry for late answer. I was gone on holidays...
There is a limited number of parking space at the hotel.so I would advise you to call in and have it reserved before the arrival. However, just across the street there is a large open space parking.also on the 3minute walk distance there is an underground parking with surveilance cameras. Both those parkings hva every cheap rates per hour ( i am talking couple of kuna's per hour)
Unfortunately we were traveling by bus and train so didn't need parking. There doesn't seem to be any parking but it is next to a huge car park by the side of the canal and there are other car parks in Rijeka probably because of the car ferries. There may well be street parking but perhaps best plan would be to phone or email the hotel. Good luck.
Get an answer from Hotel Continental staff and past guests.