Migration assistant didn’t create User

I replaced the HD in my mac with an ssd because my old one would only boot to disk utility, long story I had to do internet recovery to mountain lion, eventually updated to Mojave and had to set up as new Mac. I’ve ran migration assistant 5 times and it just transfers the data and files from old HD and just puts them into folders under the new ssd. It doesn’t create a new user. None of my files are accessible due to permission issues. I thought everything would transfer and all my old stuff would be how it was under my old users. All it did was put the files on the empty new Mac test user I created to migrate with. Please help