I built a website years ago as a volunteer, for a non-profit. Entirely KISS methodology. It wasn't exciting, but you could find the info. I understood my code. Typed and or pasted it in a text editor. Recently, political comedy happened. I won't describe it, because "Be nice policy". Now, it's on a different host, and it took our domain name with it. It's written in Wordpress. This is not what the CEO requested, which is part of the comedy. When the CEO demanded it enough times, I was given credentials so that I could begin updating and adding the missing pages. I was to be given full credentials, able to do anything and everything for the site. I don't think that's what happened. I can't find any way to access the css or the themes, nor any way to install add-ons or add members. I really suspect the "helper" retained the admin rights and made me an editor or below. I was hoping someone familiar could tell me a quick way to confirm. Would a screenshot of my dash help? I could ask the "helper" but my confidence in getting a straight answer is pretty low.
In my WP installation (where I am admin), I see a menu point "Users" on the left hand side, which shows me a list of all users, along with their roles. So that list will tell you what role you have, or if you don't see that menu point, then you're not an admin.
(This is on WP 4.9; I suppose the menu could be somewhere else on WP 5.)