I downloaded a pose for the CAS for my sim

I went to a site on twitter and downloaded a pose package for my mac. Instructions were to download and move to mods folder. I pulled it from download , moved to desktop, then opened up mods folder and put it in there. Went to start sims4 and when it loaded, a box popped up showing me the items in the pac, clicked OK. Went to CAS and made a sim. Clicked till I found the pose pic and uploaded it to the gallery. Everything went fine and worked (as far as I know).
I downloaded a couples pack and did the same thing. Went to CAS and made a couple, clicked several times and couldn't get the pose right so I went and checked the site and you can only have 1 pose set in mod folder? So I removed it. I "moved to trash" both of those pose packages thinking I did something wrong.
When I exit the sites on tumbler, I keep getting a box pop up saying to download and install flash player (something like that)? I just exit out of it. Isn't that something you need to make poses? I don't want to make poses, I just want to use the poses.
What did I do wrong?
Since I deleted the pose package I used on my sim on the gallery, will it mess my sim up?

Hope you understand, I really shouldn't fool with this because I don't know what I am doing, LOL