Get polygons and PLACEID from pbf files c#

I’m new to OSM
And a little confused
I need to make OSM calls to get PLACEID and Polygons by locality name
Today all this is done with API calls
I want to download the files needed and access them instead of API calls
Can anyone give me guidance / tips
Oh,Develops on NET.

What Frameworks have you tried so far listed at the OSM wiki at ?