It is helpful to think of Albums in iOS Photos, not as physical folders, but as organisational tags. The Recents album is special in that it lists photos added in order of their import, not necessarily in the order of their creation. A photo will always be in the Recents album. This is useful when adding photos from other sources other than the camera. However the Recents Album is not the primary view you have to work with.
If you use the Library tab, from the bottom control bar, you will see photos sorted by their creation dates, and you can also summarise by year, month, day, or view all continuously.
When the iPhone has had a chance to process the files you can view photos sorted by location (where they contain location data of course), and lots of other categories besides, by selecting them in the Albums tab, again in the bottom control bar.
As to your previous folder structure, it is unfortunate that that has not been translated as you migrated. Unfortunately I can't advise on why that happened, having never migrated from Android. You may have to recreate your previous folder structure as Albums in Photos.
Note, as I said earlier that Albums are more of an organisational tag, a photo can be added to more than one Album at a time. This is useful if a photo merits being in more than one Album at a time, say holiday snaps & dogs you saw on holiday, but note, it does not duplicate the photo, you do not waste space by doing so.
Some time spent familiarising yourself with the interface will present all these things to you in time. Be sure to read the iOS User Guide.
