Hello! That sounds like an exciting trip. Here are some travel tips for your visit to Mexico City, Cancún, and Guadalajara.

Best Time to Visit:
The best time to visit Mexico is during the dry season between December and April, when there is virtually no rain. The coolest months are from November to February, whereas March to May is hotter.

Route and Accessibility:
All three cities have well-connected international airports. Internal travel can be through domestic flights, buses, or car rentals. Metro and bus services in Mexico City are efficient and affordable, while in Cancún and Guadalajara, taxis and buses are more common.

Accommodation and Booking:
There's a wide range of accommodation options in all three cities, from luxury hotels to budget-friendly hostels. Booking.com, Airbnb, and local travel agencies are good options for booking accommodation. It's advisable to book in advance, especially during peak tourist season.

Clothing and Essentials:
Pack lightweight clothes, but do carry a sweater or jacket as it can get cool in the evenings especially in more elevated areas like Mexico City. Don't forget sunscreen, a hat, swimsuit, comfortable shoes for sightseeing, and any necessary medication.

Health and Safety:
Take usual travel precautions - keep your belongings secure, be cautious in crowded areas, and avoid isolated or poorly lit areas at night. Use bottled water for drinking. Mexico's healthcare system is good, but travel insurance is highly recommended.

Local Etiquette and Respect:
Mexicans are warm and friendly. Learn a few phrases in Spanish, it will be appreciated. Respect local customs and traditions, particularly in places of worship or cultural sites.