Having problems with permissions although I am admin

I recently purchased a new laptop. It was set up in the store, where they created a local account, with my name misspelt. I switched to a Microsoft account, for ease of use. However, I am now encountering some permissions problems. I am unable to delete some folders, because of inadequate permissions, and when I tried to replace the multiple user lock screen picture
it said that I required permission from my misspelt local account. How can I either transfer all permissions to my Microsoft account?