There's nothing wrong with the equipment you were sold, or the instructions you were given.
There are several fermenters out there that don't have airlock bungholes added, and don't need airlocks on them.
And are perfectly fine.
Some you do need to drill,
while others don't and the lids don't sit all that tight on them.
There's nothing wrong with that at all, And the mr beer fermenter doesn't even have an airlock, and SOMEHOW beer manages to still ferment in those things.
An airlock is nothing more than a valve to keep the lid from blowing off and painting your ceiling with your beer.
The bad stuff are not ninja acrobats, they really can't get into stuff. The co2 coming out will prevent anything getting in.
The airlock is one of the most superfluous things in brewing, that new brewers seem to put the most stock in.
You really don't want an airtight seal on your fermenter. The co2 coming out of there would protect your beer. In fact many folks with arthitis and other issues don't snap the lid down on their buckets anyway, and may folks just put tinfoil, plastic wrap, metal cookie sheets or even plexiglass sheets on top of the bucket instead. It's really not crucial to be tight. The bad stuff are not ninja acrobats, they really can't get into stuff. The co2 coming out will prevent anything getting in.
In fact you don't want a "pressurized" bucket, if you have one, then at some point you will end up with a ceiling full of beer. I've had that happen when the vent (airlock) gets blocked by a freak hop cone, and it wasn't pretty.