Error 36 when attempting to Move or Duplicate a Photo Library

After numerous hours reading and trying all and every suggestion I can find online for a fix to this issue ...I'm still at a loss. Bought a new Macbook so am trying to clean off and retire my old MacOS High Sierra and want to move all Photos Libraries onto new Samsung T7 SSD's formatted to APFS. My libraries are organized in Albums, keywords, etc. so want, if possible, to keep them that way. What have I tried: Permissions on Library are Read & Write, learned to use Terminal a little and ran "dot_clean", tried to duplicate the library - same error 36 code came up, made a Photos Library Copy on SSD and tried to manually copy over the subfolders in the Package Contents but the instructions did not explain what subfolders to copy so I copied at the Year subfolder - added the '.photoslibrary' extension and when I tried to open as a Photos Library I got a "Cannot Import Items" error with "file format is not supported". Now I read this indicates that Photos is not recognizing the structure or format of the moved files and need to rebuild the library, not just move the files, to fix this.  I want my library to stay intact, will rebuilding the library fix this issue or just destroy all painstaking organization done. This is only 1 library I'm trying to move and all are quite large with Albums, etc. I do have a current Time Machine backup on a separate external drive. I have also read it could be a problem with long image file names, I do have some of those - should I try to extract these images from the library and try moving again? I'm not sure what to do but if anyone has any experience with what actually works, I'm all ears. Thx