If you want to put maps on it something like the eTrex Legend HCx would have much more room for maps (on microSD).
But I actually did my first geocaching using an old non-color Garmin GPS 45 from 1995 with no maps (except tracks I made myself wandering around). So the Venture should work fine, especially if you have an automotive GPS to get you in the neighborhood.
If you want to put maps on it something like the eTrex Legend HCx would have much more room for maps (on microSD).
But I actually did my first geocaching using an old non-color Garmin GPS 45 from 1995 with no maps (except tracks I made myself wandering around). So the Venture should work fine, especially if you have an automotive GPS to get you in the neighborhood.