Hiya...
not a vivitar/pentax expert... but I remember this being a competitior to the pentax k1000 (a classic, circa 1980), the k-mount is the screw mount that the old pentax takes so you should be able to pick up a couple of cheap secondhand lenses.
other than that specs are good with ttl metering, ... but should be good to learn on!
The only thing you'll have to chekc is the actual age of the camera... The older zoom lenses where not up to todays standard and most professionals didn't start using them until mid to late 80's...
a..//