That really depends on what direction you are going in. Cobras, Mambas and Aussie elapids are Definitly not for the beginner. Niether are large vipers.
I would recommend a number of mildly venomous opistoglyphic species first such as Mangroves, Vine snakes or a FWC (less consequence if you get tagged and they will start your education on working with faster moving snakes.
For viperine experience I prefer the small S. E. Asian vipers of the genus Trimerserus (my first true hot was a Pope's). These are smaller snakes that are easier to work with.
For crotalids; you can't beat a pygmy Rattler. They are short tempered but small and not as dangerous as their larger cousins. Good enough to teach you to respect them.
In all respect I do not recommend the keeping of venomous as it intails a very big responsibility along with the pleasure. Keep in mind that it is the same thing as keping a loaded gun in your house that has a hair trigger.
That being said; good luck!
Frank
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"The luxury of not getting involved departed with the last lifeboat Skipper..."