The oldest building would be the cathedral built between 1628 and 1633 although the city walls were built between 1613-1618 and are still standing and complete

Signal messenger has a note to self function that can be opened on the phone and windows that will do text and small files

I would look into grinding and sanding it flat and a resin coating to seal the surface. There are YouTube tutorials to DIY it if you are price conscious

You’ll want to avoid pornlemmy.com and lemmynsfw.com . Lots of nudity and unwholesome behaviour depicted there

Edited for spelling