I would like to remove the "Site Profile" from our forum since we don't use it.
You can edit the "Site Profile" text of this link in Dashboard > Forums > Phrases admin page. Just search for that phrase, edit and change it.
In case you want to remove it, you should put this CSS code in Dashboard > Forums > Settings > Styles > Custom CSS Code textarea. Then save it, delete all caches and press Ctrl+F5 on forum front-end to load new changes:
#wpforo #wpforo-wrap .wpf-pp-shop-menu,
#wpforo #wpforo-wrap .wpf-pp-site-menu,
#wpforo #wpforo-wrap .wpf-pp-forum-menu{ display:none; }
That CSS code didn't work. Did I do it right? I deleted all cache. 
Ok, I updated the code, please change it and delete all caches with Ctrl+F5 on front-end before checking.
Nope, still there. Are you sure that is the correct code?
Yes, it's correct code, just make sure you've deleted all caches and pressed Ctrl+F5 on forum front-end to reload CSS files and reset browser cache.
Just did, I have tried it a few times but it's still there.
When you say "delete all caches" I assume you mean this: 
And here is what the custom CCS code field looks like: 
And yes, I did press Ctrl+F5, I even tried it in different browsers and on different devices.
Your forum URL please.