There are much better games!
Ticket to ride yes. Get the original or Europe first. Your 9 year old will be fine. The sets such as London, Nordic etc are great too but often for fewer players (Nordic is max 3 players).
Look at catan, Carcassonne, pandemic, through the desert, 7 wonders, azul, splendor, tsuro, tokaido, takenoko or smaller table top games like rhino hero, deep sea adventure, zombie dice,dobble, exploding kittens, nyet.... the world of board games is vast and wonderful!
It totally depends what you like. There are a lot of very involved character/ role player games and games that inhabit strange worlds but also lots and lots of games that are just interesting and fun and don't involve deep levels of geekery (nothing wrong with it, I'm a geek in many ways just not in gaming).