I know I'm late, but in case you're ever wondering again, here's a little more advice.
I would recommend getting a Connection version. That was definitely my favorite Tamagotchi era.
Here's my two cents about each version:
V1: This one's okay for beginners. It has the smallest growth chart, smallest amount of games, and no shop or special foods or anything like that. Normally I'd say start with it, but since you already have a Tamagotchi now, I wouldn't bother.
V2: This has more growth possibilities, more items, more games, and is just generally more developed (read: fun) than the V1. Once you've gotten used to the mechanics, definitely give it a shot.
V3: Ever since TamaTown shut down (curse you BanDai give us back our TamaTown
), this is essentially the same as the V2, just with different characters. I still recommend it, though.
V4/V4.5: These two are some of my personal favorites. Definitely check them out once you're more used to everything, since it does have more mechanics than the others (like school, work, and skill points).
V5/V5.5: These are another two that I like a lot, though again, they're not really for beginners. The family bonding mechanic might be a little tough to work out at first, but you get used to it.
V6: Sadly, I wouldn't recommend this for a less experienced player. While I do like the concept, the buttons are not as responsive as they are on the others, which is really a problem on a music-based toy where a lot of things rely on rhythm and timing.
The Connection era is my favorite because not only were the actual versions really solid, but the style was cute and happy, but still fun and quirky.
Tl;dr: Connection is best; V4 > V2/3 > V5 > V1 > V6; bring back TamaTown; Lovetchi says "mechanics" way too often.