Healthcare and techlevel in a medieval setting

[SSB_Shadow]

Hey everyone, this is my first post on the website.

I am also starting a new campaign with D&D 5e. I have played it some as a player but never as a DM. But I do have 10+ years experience DM:ing Star Wars RPG so I am familiar with being in this role.

So my biggest obstacle is adapting to a world I usually fill with science fictional pieces into medieval pieces. The level of technology, fashion sense and level of medicine is a bit of a challenge to adapt.

So I'm wondering: how do you handle things like health, disease, body hygiene and oral hygiene, etc?
Do the people of Faerûn know about virus and bacteria? Do they understand why diseases happen or are they always blaming it on superstition? What about oral hygiene; does everyone have bad teeth? According to artworks glasses seem to be invented but how common is that?

Most of this might be obvious. Or can be solved by "magic". But in my upcoming campaign there has been a span of 30 year of non-magic in the world so much of that dependency will be lost and the inhabitants are forced to adapt.

New technology?
I am also thinking that without magic for so long, people will turn to alternative methods and start inventing new things.
What would be considered an advancement in technology without going too crazy? Would steam-power be logical or is it too far ahead? Anything else?