This is what I have learned
My understanding is that most ExPats are working here- and therfore have a built in group of people- in their company. My only English speaking friend in Guad is my neighbor- who is the Canadian Counsel General- she told me there was an Ex Pat group that used to meet at a rest. here in Zapopan- but when the main players got transferred- the group died off- and I never really pursued it -since I already had long time Mexican friends and acqaintances.
There is the American Legion ( but have never been there)-have been told it's a bunch of older retired folks- who have lived here a while

Mexicans are very gracious, friendly and helpful but Guadalajaran's consider themselves - to be the most sophisticated-and the most European in all of Mexico!! -they think anybody from Mexico City is a wannabe-even if they've lived here for 25 years. Second family names (mothers family name) are really important - who your parents or grandparents are ( old family names ) or were-- in many cases determines your social status in this very class concious city. Its a city of WHO YOU KNOW- and who you're related to.

Callif. is SOO Different- so many people from everywhere- people mingle and talk with everyone- and San Francisco is so open it's easy to meet people anywhere-

Mexicans see their family as their primary social circle- Husbands- wives and their children, then Parents- Grandparents- Sisters & Brothers, their children, Aunts & Uncles, Cousins and their wives & husbands and their children, God children etc etc- they see their main family every week and with all those relatives- there is always a family gathering taking place.

Next the old friends- who generally are a select group- who always socialize together and you almost never get into this group --unless you are connected to a Mexican. There can be 2 groups- everyone knows each other and for Xmas etc the 2 will all get together- but they only sit and talk with their own group- I find this really strange, and sometimes find myself just being the observer of the culture.
Favorite pastime- Dinner for some occasion-Birthday etc around 3-4pm and then sit around the dining table for 6-8 hours talking and drinking- leave about 12pm then stop off with some of group for tacos somewhere in city- get home at 230-3am- or you may meet your group in a Restaurant at about 930pm eat and talk until 130-2pm - the city is open all night- Taco places have long standing corners for years- all over the city-You will see whole families, Grandma, kids etc eating in the more popular taco restaruants at 12 am on the weekends- most popular time of night for tacos 3-5am-so parts of the city are going all night.

Young singles are out all night- there is a bar next to the new mall-near my house on Fri and Sat nights 400++ cars lining the streets for blocks- the place jumps until 6am-luckily not close enough to hear.

From people I know who have lived around the world- This is pretty normal- It's hard to fit in with locals ---without something in common like work.