We miraculously managed to get a good deal that we could blow all our savings on to get this new HVAC unit installed about a year ago. In the last few days, it's suddenly started producing a sour smell, particularly in my room. Looking up the issue, all I see is people saying to call someone to get it cleaned because it's mold and/or bacteria build-up. I changed the filter, but the one that was there was barely dirty at all, so I don't think that was much of a fix.
I can't go into detail, but there's a lot going on right now and we can't afford much. We barely even have time to organize fixing something like this. But I don't want to take risks with our health.
Can I get some advice please? What would y'all do?
*also my god the youtube algorithm-fueled thumbnails that come up when searching for tutorials on what to do about this are truly horrendous, look at this shit, just straight up embarrassing

I watched this video to find out about cleaning the drain line, it seemed simple enough so I marched down to the interior AC... unit... machinery... giant grey boxy thing to find the PVC pipe to uncap, but I don't see anything like this coming out of the unit I have. The closest thing is a long tube that comes out and snakes down into a much thicker, larger PVC pipe. Not confident that's the same thing. Thankfully I had the foresight to check before pouring out a cup of vinegar, at least.
Does that bigger PVC pipe go into the floor?
For the sake of keeping my info private, I'll DM ya some pictures I took
I found a YouTube link in your comment. Here are links to the same video on alternative frontends that protect your privacy: