Loading my old Hard Drive into my new SSD HD

How are you trying to move the data?

Have you properly formatted the new SSD?

Use Disk Utility to format the SSD with a GUID partition scheme and the APFS format.

Erase and reformat a storage device in Disk Utility on Mac - Apple Support

If the SSD came with any utilities from the manufacturer, DO NOT use those. They are unnecessary and often cause problems with the OS.

Use Migration Assistant. You will find it in Applications - Utilities - Migration Assistant.

Apple explains more in Transfer to a new Mac with Migration Assistant - Apple Support