You are in luck. There are SO many places to fly fish within an hour of sacramento. Try heading to Kienes fly shop for more information. Depending on time of year & Season, You could try the American River south of Folsom for Shad around May, The Feather & Yuba for trout, salmon and steelhead, the delta for Stripers & LMB & Panfish or the sierras for a bit more of drive.
Any way you choose, you're in a good spot for fly fishing.. Hope this helps.