There aren't any really big cities in Slovenia.
Even the capital only feels like a big town.
Slovenia is a wonderful country, get onto the rural back roads
for the unspoilt feeling.
We stayed at Bled last year when we toured the Slovenian Alps. Not a bad wee place Lake Bled. Some OK pubs, good restaurants (fantastic custard slices) and cheap as chips hotels. My last visit was in 89, place has changed a lot since then.
We went two years ago in the motorhome, seems a bike friendly place as lots of the hotels around lakes bled and bohinge were offering deals for bikers, even Harley owners!!! As the previous post says, nowhere is very big, really enjoyed the country and will go back again.
We stayed in Bovec last September, it's a good location and close to good roads, there are plenty of cafe's bars and restaurants in the town, I would definitely stay there again.
Most na Soči is a very nice little place in the Soča valley. The Hotel Lucija is a worthy place to stop at with very friendly owners. Have stayed a few times now.
See your parallel post in the Travel section. The hotel might well depend on where you decide on riding... and your riding may well dictate your hotel.
Bled or near there may well suit you, perhaps? If so, the suggestions in posts #8 and #9 would be good ones.