I'll let you in on a little secret, unless you are teabagging your wort after spending a week in the same underwear you probably don't have to worry about infections. Yes, sanitation is very important, but when you begin to brew your are hammered with the issue to the point of making you paranoid. Hops and alcohol combine to make an environment that is toxic to most all bad critters out there, so all you have to worry about is getting an infection of stuff like lacto, pedio, and brett (which won't hurt you they will just ruin the beer)...here is an excellent thread to help you get a handle on recognizing them:
https://www.homebrewtalk.com/f127/pellicle-photo-collection-174033/
Yes, you could concievably get mold growth, but that tends to be white mold which won't hurt you and you can rack the beer from underneath it and be fine. I have been brewing for a decade and in that time I have tossed a few beers because the recipe sucked (in fact my pumpkin Belgain dubbel is getting tossed this weekend as it didn't turn out as I had hoped) and one time because the seal on the fermentor broke and it got oxydated into an acetaldehyde bit of nastiness. But, never have I had an infection or even mold growth. I clean my equipment with oxyclean, occassionally break-down the 3-piece ball valves to do extra cleaning, and sanitize everything post boil with Starsan (I don't even wait a minute for contact, maybe five seconds) so you can see that I clean and sanitize but I'm still pretty lazy about it and that has been effective for a decade.
Your nose will tell you a lot, but you need to teach it first. Fermentation can put off all sorts of odors ranging from bready, yeasty, fruity, sulfury, and more. You can get all sorts of off-flavors and odors that have nothing to do with infection but ruin your beer none-the-less. I would highly recommend you learn this as knowing what is going on is immensely helpful in trouble shooting and becoming a better brewer.
