I watch so many movies where I’m thinking “Oh, no, this person is ALL WRONG for that role!” so despite having absolutely no qualifications whatsoever, I think I’d be great at casting. Your move, Hollywood!
How about you?
President of the USA
Movie critic.
I helps that as long as you’ve somehow gotten the job, you can say literally anything and never be wrong.
Bobsledding. In the Olympics, the difference between the winner and last finisher is not exactly weeks. I lean with the best of them. 
WWII Bomber Bombardier. I’m really good with gizmos like those old bombsights. I could lay the egg right on top of the munitions factory, you bet!
Despite having zero experience at football coaching, I do think I’d make a pretty good offensive or defensive coordinator, or at least strategist (I can’t be a head coach, because that requires all sorts of people-motivation charisma that I like, but I’ve seen far too many senseless, nonsensical play calls and know better).
I have no official qualifications as a bicycle mechanic, but do have years of servicing my own and family bikes, and volunteered at a charity bike shop that fixed donated bikes to give away to the needy. I would enjoy the job: I would think I would be a good bike mechanic at a bike shop and hope I could make that a part time job when I retire. I have contemplated working at Target assembling bikes during the pandemic so I could have some “official” experience with the role.
That’s a lot of evidence though. 
I have always designed my own living space and I think I would make a good interior designer.
There are probably plenty of jobs I would be competent at, but great? Probably none.
Lawyer. I’d hire a good law clerk and I could do the rest with my eyes shut.
What the hell, let’s go for the whole jelly doughnut, and just say Judge.
I’m sure I’d be a good bookkeeper. Not an accountant - I don’t want to be responsible for anything approaching complicated decision-making related to taxes and such - but straight-up keeping track of expenses and income? Hell yeah. I’m really meticulous about that sort of thing, and find it oddly satisfying and soothing to keep track of numbers. So in addition to being good at it, I’d actually enjoy it.
Lyricist.
I don’t really listen to music, I have no interest in modern pop or trendy crap like that, and there are some styles of music that make me want to bang my head against the wall, and of course I can’t play an instrument, but I still think I’d be pretty good at writing the rhymey word bits.
I could be a great poet,
Though, knowing me, I’d blow it.
I would design and build some spectacular sailing yachts. Not the obscene multi-million dollar ones that only the super wealthy can afford. But yachts in the 12 to 20 meter range. None of this multi-hull space ship looking crap. Proper classic yachts as beautiful below the waterline as above, center cockpit, composite with right amount of bright work, ketches and cutter rig sloops. Fit for blue water sailing.
Straight Dope moderator.
I’m very good at devising solutions that piss off all involved parties.
Had to be posted.
Big time record producer. I’d be a bad small-time record producer since I’d need to have sound engineering skills as well, but if I had someone to do that for me, I think I’d be able to provide input to what sound we should use and how to achieve that and which tracks to include and how to arrange them so that it meshes with what I and the band would like.
Detective. From what I’ve seen on TV, all I need to do is arrest the third person I interview.
Movie critic.
Stock trader. Because I’m good at picking random acronyms and making magic with 'em.
Tripler
Stock advice? KMAGYOYO.