"We" did not do this - most people on this site are users of Adobe's technology, just like you.
If you have a valid license for Acrobat XI, you can download the installer from here: Download Pro or Standard versions of Acrobat DC, XI, or X
I use Acrobat on a daily basis, and I also don't know where all the functions are - and I don't have to because I can use the tool search function in Acrobat DC: You have two different areas that allow you to search for functionality. All that is required is that you know the name of the feature.
At the top of the tools pane on the right hand side, there is a search field, and second way to search is once you select the "Tools" page - again, at the top of the page is a search field. Once you start to type, Acrobat will display all matching tools, and you can then either pick the enclosing tools area, or you can actually launch the tool from the search results.
Thanks. "You" was directed at Adobe in general out of exasperation and frustration.
No I don't have the valid license for any of the previous versions because I was using them via monthly subscription. Yesterday I wanted to renew that subscription (I let it lapse for a few months as I didn't need it) and got this garbage instead.
Worse yet after I posted this and opened the AutoCAD files I was working on I discovered that DC up and inserted itself into CAD and also ruined all the PDFs I had previously imported into various files on which I was working. There was no fixing that, I had to waste hours to import them again, scale properly, position, etc etc.
So yeah I'm mad.
Also I think that companies shouldn't force "upgrades" (I use this term loosely because this DC crap is a huge downgrade) on people who don't want them. My first reaction is to stop using their products. Which is where Adobe will be heading as soon as I find suitable replacement. But I can't do it now because they made me severely late and backed up with all my work.
You should be able to install Acrobat XI, and during the installation select to install in "trial/subscription" mode. Once installed, you should be able to log in with your Adobe ID and use it.