You don't necessarily need the thermo/hygrometers, but it definitely makes life easier.
You can get 5 or 6 combo meters small enough to fit in mason jars for about $20 on Amazon...Then another $20 or so for the watch batteries to power them, if they don't come with.
Wherever you dry them, just try to put them in jars when the outside feels dry, and air them out again once the outsides are moist again.
They'll need the most attention / air time the first day or two. After that, you shouldn't have to worry about mold, just letting them get too dry. You'll find your groove- We're just trying to help you find it sooner than later.
At least you've gotten it too dry, rather than too wet.
You can still smoke dry stuff, but you don't wanna smoke bud mold!