i just hate to hear folks get rid of pets because they move.
corn snakes are great for beginners and don't require as much attention as the bearded dragon and gecko you mentioned. they are real docile and adjust well to handling. be sure a corn snake is what you really want. do your homework before getting one.
i got my first corn at a pet store then my others from breeders at reptile shows. (i have 5 snakes, 3 of them corns) if you look up the 'events' schedule here on kingsnake you may find a show in your area. that way you can look at different corns and other reptiles. most vendors have resonable prices too.
an older snake, say at least 6 months, would fair better at being left alone vs a hatchling. i've left my snakes alone for a few days and they were ok. i just put 2 water bowls in each tank and made sure the lights and timers were set right. i even did a 'trial run' by getting every thing set right and left them alone for a week to see how they did while i was still there. but if you can have someone come by to check them would be even better.
there is no set time on when to get one. it's when ever you think your ready. but like i mentioned do your homework first and you will be happier in the long run.
just my 2 cents. enjoy you new addition when you get it. 