I've never been into Mexican food for a simple reason:
Go to an Indian Restaurant and you will be greeted by Jarveesh, Pradeep and his staff
Go to a Chinese Restaurant and Lin Ho will welcome you with open arms
Japanese restaurant - even the local sushi stall - girls and guys look like they are straight out of Kobe
I will not even attempt to pronounce the surname of the lovely couple who own the Old Bar "Thai Tea and Table" restaurant here.
Mexican Restaurants all seem to be run by fat bogans called Sheila and Doug who will happily microwave you a takeaway container of something swimming in red crap with something that looks like rolled up pancakes lurking under the slop.
Mexican has always seemed too much of a learning curve. Might get onto it eventually as I live on garlic and chillies.
By and large, Bribie, you're right, but should you wander down Melbourne way, check out Mamasita's. Two guys who run it are from NYC and Mexico City. They've backed off a bit on the muy autentico parts of the menu, but what's left is still good. On the other hand I know of a Mex restaurant in a town east of Melbourne whose name I've conveniently forgotten, where the cook is from Monterey, the Mexican one, and uses her mother's recipes. Trouble is mama couldn't cook; would you believe evaporated milk in damn near every recipe?
As for the original question, where to start, try getting a range of chiles (not chillis, aargh). Look in odd places. An Indian store in Belmont has pasillas, anchos, habaneros, guajillas, moritas and more. Get a source for quality tortillas. Then start with recipes for the various classic enchiladas. Fajitas are verboten. Tortillas are with few exceptions made with corn. In Mexico tacos used to be strictly street food, until tourists badgered the restaurant owners.
I promise I'll post a recipe for enchiladas suizas en mole poblano. Tender chicken strips and gruyere cheese rolled into fresh corn tortillas and baked in a sauce redolent with four chiles, bulked with ground pepitas and blessed with flavours as diverse as cumin, cinnamon (very light) and bitter chocolate.
Bribie, given your stated tastes, try a simple sopa de ajo (garlic soup). Dice fine every last clove of a large garlic, soften in butter, add a litre of real chicken stock with a little marjoram, simmer a few minutes, pour into crockery bowls, top with toast and a good Mexican queso fresco (halloumi is a better substitute than cheddar or Monterey jack), and stick under the broiler to melt and lightly brown the cheese.