Hydrometer is not for measuring alcohol, it measures the density of the liquid
which depends on others things as well (in this case mainly of the amount of
sugar in the liquid). Homebrew shops sell winemeters that are meant for
measuring the alcohol content of wine, but they will only give the correct
result if the wine contains no sugar whatsoever (the wine is dry).
You can only get 16-18% of alcohol by fermentation, after that the yeast
dies. Thus your claim of 24% is impossible.
Since you only used yeast and applejuice (and sugar, I assume) then there's
no chance of anything dangerous appearing in your wine, unless you sanitized
things badly and the wine has got some sort of infection from somewhere.
If this is the case you can taste it for sure, so if it tastes good then it's safe.
Naturally you can kill yourself by drinking the whole batch at once, but this
doen't mean there's anything wrong with the wine
I have no experience on freeze distilling, but I can't see any reason why it
would create anything dangerous since it only removes water.
For storage a cool place dark place is good. Since you didn't use any
preservatives that are normally used in wine then it probably won't stay
drinkable for years like normal wines do, but if you bottle it in well cleaned
and sanitized bottles then it should be ok for quite a long time. Again, if it
tastes good it's ok for drinking.