No you will be fine doing this in a ventilated shed. Just don't slosh solvent around willy-nilly. If you spill it, wipe it up and then leave the room for a bit.
Masks of that sort eg N95 will be of no use as the solvent will diffuse through them in the air, the molecules are tiny they are about 10^-9m in diameter whereas N95 is designed to filter-out particles (eg covid19 droplets) that are 10^-6m in diameter about 1000 times bigger.
However for a small job like a jam jar full and a piece of furniture such as your workbench you should be below the exposure limit if you do the work in a well ventilated room. Open the window of your shed/garage and you should be fine.
The key thing is not to over expose yourself. The long term effect of these solvents is damage to your nervous system (ie increase the likelihood of nervous deceases such as Parkinson's, MS etc) . The occasional finishing of jobs will be fine.
Professionals who wax furniture all day for a living should take extra precautions such as having a ventilated cubicle for this kind of work for use a forced air face mask. For your job don't worry. The key point is don't slosh the solvent around willy= nilly (sorry English term - don't splash it everywhere as if it was water).
Oh and the final point is white spirit is 5 times less hazadous so you can wax five times more for the same hazard to your heath, so be a bit more careful with Turpentine.
