Congrats and good luck! I was in the same boat as you (although I'm "slightly" older than 29); wish I'd started sooner.
You can definitely find a lot of good/cheap (and not so cheap) used goalie gear on Kijiji. That's where I accumulated most of my stuff -- Facebook marketplace is another place to check out. I bought my mask off of eBay (although not recommended as fit is important); I would generally stick to local sources as the selection is good and it'll likely be cheaper (since you don't have to pay for shipping). 2nd Chance Sports on Edmonton Trail might be worth a visit as well.
As someone who is 6'4, you'll probably need pads that are at least 36" (although the actual measurement is based on ankle to knee, not height). And unless your plan is to flop around Hasek style, getting a set of butterfly style pads will also help (although the actual butterfly technique takes some practice, i.e. backside pushes, and sliding from side to side). Note that the newer style pads are typically very stiff; if you're someone with less hip flexibility (like me), you'll benefit from softer pads that flex more at the knee (to help close your five hole).
The rest of the gear is up to cost and personal preference; the newer stuff will be a lighter, but pants, blocker/glove, chest protector, etc from 5-15 years ago will still work fine for a beginner.
For me, skating was the toughest part to start with; once you learn the basics (shuffles, t-pushes, and c-cuts), you can start working on stopping the puck. Lots of goalie drills available on youtube.
Feel free to send me a PM if you're interested in more info; I've accumulated a bunch of gear over the past couple of years, but most will likely be too small for you. You also might want to check out Discover Hockey as well (they have spots for goalies, including goalie specific coaching):
https://www.discoverhockey.com/portf...ockey-classes/