I was obsessed with the Dixie Chicks as a child. My very first favorite song, from what I can remember is Wide Open Spaces, which came out in 98 - so I was only 3 years old, but I remember singing this song so much when i was about that age
Up until I was about 7, all I listened to was country because that was all that I was exposed to. So, as an added bonus I'm adding my "first love" of songs outside of the country genre - when I carpooled to school one day with a friend and heard Complicated by Avril Lavigne on the radio I instantly fell in love with that song and pop rock music - and "Let Go" was the very first album I ever owned!
Edit: I really like my response so I'm keeping it lol but I think I misunderstood your question....are you asking what song reminds me of my first love? If so - I've never technically been in love (at least not with someone who has been in love with me back) anyway, long story, but ill post the song that reminds me of that person i liked for a very long time but was never with
My first real music love was The Beatles as an 8 year old. My parents brought me this Beatles Hits for Kids cassette tape and I got obsessed with songs like "Hello Goodbye", "Eight Days A Week" and "Ticket To Ride", it's a pretty predictable pick tbh and it was before I really got hard into the pop music of the time.