The pure fingerings aren't all that hard to deal with; it's the covering of "tuning" keys in an often illogical fashion that is what will trip you up.
Put another way, on the clarinet there are but four semi tones (G, G#, A, A#) that are routinely used below the altissimo that add "resonance" keys to the mix. (And, yes, I know that some go further than that in search of perfection with the lower notes - I'm talking about the mainstream here, not the tributary branches.)
On the bassoon, depending on whose fingering chart you adhere to, these resonance fingerings number almost as many are their are fingerings. Much more memory effort required to keep it all sorted out, and much harder for an adult to memorize.
I came to the bassoon by the back door, picking it up during summer band when there were none in attendance. After a year or two, working with a fingering chart and a few hints from a former band director (who got fabulously wealthy through his investments in Sintex, the maker of the first legal birth control pill here in the US), I managed well enough.
However, one thing that I never adequately implanted into my thick head was the note names associated with the bass clef note heads. Instead, I played (and, to a great extent, still play) the bassoon by the "Push the button, monkey!" approach.
So, when I see a note head on the second line from the bottom in the bass clef, I think "(w) xxx-xoo-o" rather than "B". Cumbersome, but the sort of approach you would expect from a treble clef-reading kid who had no teacher to help him along when he worked through the basics.
As a result, my bass clef reading skills were somewhat limited. I had the same sort of system for playing bass clarinet parts in bass clef. (Unfortunately, my grandfather only taught me what I needed to play band parts, even though he was fluent in both.) And, when tenor clef crops up, it's time to start making notes in the part.
The moral of the story is, learn how to read bass clef...
My bass clef epiphany came when I watched my son (who was an accomplished bassoonist up to the point that his semi-pro hockey career got in the way) run a few scales on my newly overhauled bassoon. At that point, I noticed the correspondence between the "holes" on the bassoon and the chalumeau register fingerings on the clarinet. That made it a lot easier to figure out the bass clef.