This area has a parking lot at the entrance and you can walk the easy way or the longer route. If you are lazy, the moment you enter, they have multiple viewing spots that are just there. This place is suitable for old people as well. It's free entrance but you gotta pay for parking.
Worth to spend around 1 hour there (depending on how far in you want to walk).
You can visit the bear park and this before you check in to the hotel at 3pm, since by the time it's dark, there's nothing much to see so I suggest in the morning, visit both Jigokudani and Bear Park first.