Unable to use menu plug ins

Apologies in advance, there appear to be a few threads but my tiny mind doesn’t really understand so I am looking for a really dumbed down answer please as I am not overly familiar with css or WordPress, I am just learning.

I have tried installing a number of menu plug ins and evertime i get an error saying that I don’t have permission at access the settings and therefore use any of them. I updated my WordPress to the latest version.

Can someone pleae give me a step by step of how to fix this and why it is occuring thank you?