Honestly, this thread is such a lovely and wonderful idea since I'm the same in wanting to know about how people got into the game too! City Folk looks like such a fun game although I never had the means to ever play it. It's cool that you're able to make own your character after playing as your sister's characters and doing all the tasks for her! Ahhh yeah life simulation games can be pretty fun too so it makes sense as to how you got into the series! Thank you for making this thread and sharing your experience as well!
As for me and my start with Animal Crossing, I was always curious about the original game when it was first released on the Gamecube back in 2002 but at the time seeing as my parents wouldn't buy me a gaming system and having not grown up with playing video games, I actually didn't get fully into it until 2014. All I remember was seeing how cute the villagers were and you got to live with animals in the same time. There were commercials for the game if I recall watching on TV and was pretty odd for me since I didn't understand it back when. I also would see advertisements in magazines, Youtube videos, and whenever I went to the video game store, the boxes for the games on display especially the first game and City Folk. There were times I saw gameplay screenshots for the older games and that made me excited because having never played the actual game, I actually liked the concept of the game. I envied people who could afford game systems and were able to actually play it at the time. Both the curiosity and want for the series grew over time and I vowed that I would eventually play it one day. Or at least one game if not all.
This was somewhat fulfilled when I was able to purchase my first physical copy of Animal Crossing as it was part of this special deal that Nintendo had and I remembered getting the copy of it at Walmart. I admit that I also wanted to get it because the digital version of Pokemon X at the time was part of the offer too. It was lucky that I had money to buy my first handheld system at the time: Nintendo 2DS. So that was great deal for me as a new player. Playing the game, I got to enjoy not only meeting special NPCs like Isabelle who helped you fulfill your goals as a mayor and building your town but also relax and doing things like fishing, bug catching, digging up fossils, gyroids, and other things, interacting with other villagers, and so forth. The shopping plaza always had me excited because of how it felt like a mini downtown and while the game is about relaxation, not going to lie, one of my biggest goals was to expand the Main Street seeing as I visited other people's town and admired them for not only making their town so pretty but having the shopping plaza/district feel as if it were completed. I learned many things from this game including time traveling, selling items and villagers, and how to move out villagers you didn't want. One of the earliest thing I recall is that I ended up being really into fishing since I enjoyed being able to catch fishes more than I did with Bugs. (Guess this where Blathers and I related haha). Another thing I enjoyed doing was actually going to talk to Sable and getting to not just know her but seeing her open up so that you could. I actually loved when she chatted with me about the weather to her favorite soap opera and whatnot. Quite frankly, while it did help enable the use of QR Codes in the game, the interaction with Sable made it actually more enjoyable and intriguing. Thinking back, I was able to come into the game where I was introduced to not only the NPC (classic?) characters like Tom Nook, The Nooklings, and The Able Sisters but also newer characters like Isabelle, Reese and Cyrus, and Kicks. There were many things I also enjoyed about this game including but not limited to: visiting other players (made a friend on here who gave me some Sanrio items while another helped me with a villager), Club KK, sending mail, gifting villagers, going to their houses for their birthdays, the villagers inviting me to their house or they coming to mind, trying to pass Gracie's fashion checks for her to open her store in your town, enjoying the holiday events, and definitely the music. The game also gave me a sense of not only a sense of relaxation and rest from the real world but just had the positive vibes that wasn't forced (if that makes sense) and definitely grew on me as I kept playing more of it. The music also was one of my personal favorites as I became used to it and now listen to it outside of the game for leisure activities and or to help me write.
New Leaf also helped me become not only hyped and excited for New Horizons as the years went on but the series in other ways as well--I made friends with a few people on here or elsewhere who loved the game, would try and watch more people play the games, listen to a podcast about the game, admiring people's islands through Dream Addresses, read blog entries about it on various of sites, look into buying AC merchandise, would read theories and or speculation for future games be it on here or other sites, played Pocket Camp for a while too, and or just listen to the music on Youtube and so forth and getting to play Happy Home Designer and Wild World somewhat at one point! Also, this is lengthier than expected but New Leaf is the game that really helped me not only experience my first Animal Crossing game but come to love the series even more in a sense. <3