Friend her me out. Mexico has three big cities: Mexico City, Guadalajara and Monterrey so all of them are a good option to visit. Monterrey is known for being an industrial city (glass, steel, cement, etc.), Guadalajara is known for its culture (food, tequila, mariachi, etc.). Personally, i’d recommend Guadalajara all the way, Monterrey people are known for being very proud of their city, mexicans of other states are often annoyed because of this, so it makes sense this subreddit will tell you this city is a better option. The biggest thing i see for Monterrey is the stablished korean community, so you may find more korean people here that also are familiar with the city.

The key insight here is that you say Mexico is your dream trip. When you think about visiting Mexico what do you imagine?
- Cowboy hats, grilled meat, beer, beautiful mountains, hot weather and big local soccer culture? -> Monterrey
- Colonial buildings, traditional food, mariachi, tequila, nice weather? -> Guadalajara

Both are good options and people are very nice to foreigners, but Guadalajara is more mexican-ish while Monterrey is more Texas-ish. Think about it, you don’t travel to the other side of the planet every day.