Getting In
Aer Lingus fly direct from Dublin to Cancun. An internal flight from Cancun to Guadalajara takes about 3 hours.
There is a direct flight from Madrid to Guadalajara with Aeromexico, airline which has internal flights in Mexico.
It is also possible to fly to Guadalajara from all major US cities.
There are two low cost Mexican airlines, Volaris and Vivaaerobus, they are similar to Ryanair so be mindful of the luggage allowance and the extra cost they can add through the booking process, for example: TUA ( Tax added for the use of the airport).
Getting Around
The best way way to move around is using the Uber app.
There is also a metro (tren ligero) but this doesn’t go to the airport.