First of all, welcome to the wonderful world of OSM(-editing)!! :-)
To keep track of changes on a location we use "life cycle prefixes" (https://wiki.openstreetmap.org/wiki/Lifecycle_prefix)
If you have other questions about tagging, you nearly find everything in the wiki ;-)
In this case I still have 2 remarks:
1) use the tag was:name=* + was:shop=bakery
2) if a POI is located with an address tag, the POI doens't need an address tag. In this case you can remove all the address tags ...