The Nightmare of importing RIPd M4a files on my iPhone12 from Windows AND getting blank artwork!

I am an Android phone user on Windows 11 PC NOW trying to cope with the Mystery of 'Apple' ios - Apple Music. I have RIPd all my old CDs into BOTH MP3 and M4a (and embedded the Artwork using Tag&Rename) Never been a problem on Android I usually set the Artwork at either 300 x 300 pixels or 500 x 500 pixels in size. It has taken me a while using Apple Music, Apple Device to transfer the Music File on to my Phone. Frankly the downloaded standard answer from the Forum didn't solve it for me. But using YouTube videos I have sussed it. You need to know where to put the file on your User Area for Apple Music and the Device Syn. However the few albums I have done have come up with blank artwork. I checked what size the embedded artwork should be and it seems the artwork for Apple Albums aka iphone should be min 1300 x 1300 pixels. So using my Tag&Rename changed the embedded artwork to this 1300 pixels size. But still seems a Nightmare on Apple Street! Using Apple Music I think I could edit the album and ask to ADD the cover artwork again with the enlarged image (just in case) I think. I could do with some helpful advice from an experienced Forum user and not just being pointed at standard articles. Can some one on the Apple side say what size the Artwork should be? Does it make a difference? What would be the best way to ensure the cover artwork is embedded from an Apple/ios/Apple Music point of view. I am learning iPhone because I go to a local U3A IT group. They all seem to be iPhone crazy users. Thought with my IT background I could learn the mysteries of the iPhone and help people with my IT background experience! Maybe that is a

pipe dream. Can user Help Me? I see others on the Forum seem to have problems with Ripd music/Artwork and all that jazz.