Accessing folders needing "permission" to open

How do I overcome this message: "The folder can’t be opened because you don’t have permission to see its contents." ?

I have a 10 year old MacBook Pro on which I have been writing my novel. I purchased a new MacBook Pro with the M1 chip. My wife used a LaCie Mobile SSD to migrate the information from the old to the new MacBook Pros. Unfortunately I now have folders with red circles with horizontal white bars inside of them in the lower-right corners and when I click on the folders, the message comes up onscreen.

What must I do to bypass this message and open the folders?

The long form of my novel, almost 70 sections, must be in one or more of these folders.

Thanks in advance for your assistance.

Jeff Donohue