I discovered Folsom Historic District about a year and a half after moving to Sacramento. It’s a cute little district about five blocks long. I would suggest a nice clear day and a desire for a quiet afternoon into the evening to take in the whole thing. It might not be a bad idea to book a room at the Lake Natoma Inn and make a weekend of it.
There is plenty of shopping in the small boutiques and shops. You can enjoy meals from breakfast to dinner at several local restaurants and enjoy wine tasting and or a desert at one of the specialty sweet shops.