Visited on a Friday afternoon after going to Powell's City of Books. The walk over was along a bit of sketchy areas (walked along Burnside) and the fountain area itself was a little sketchy. Litter, dirty, homeless, abandoned buildings. It was ok in the day but I wouldn't recommend going at night. The fountain itself is ok--not a major destination in itself. There was a fire station just to the south that appeared to have historical fire fighting equipment inside which was interesting.
We continued on to the waterfront and walked along the path--the area seemed to get nicer the further south we went. We walked back to our car along Morrison -- much nicer street, felt much safer.
Not sure where to park specifically for this fountain. Parking in downtown Portland seems to be a nightmare. Street parking and lots are all pay 7 days a week. The cheapest lot we saw was $4/hour with most of them being $5/ hour and $14 for the day. Some stores may have lots (Powell's books has a lot, not sure if it was paid or not, it was full when we arrived).