inept to install plugins. no upload button.

so i was thinking this _MUST_ have been covered somewhere already but after months of searching, giving up, searching again, without success, i decided to just post about it.

there’s hundreds of lovely plugins of which i’d like to install some to my wp blog (cmvblog.wordpress.com) but i don’t know how.

i’ve read a lot of guides and how-to’s and stuff. they told me “unzip php to hard disc, upload to wp-contents/…”

now, i can completely comprehend that, but where is this upload function/button/tab/whatever?
i’ve seen screens of other guys blogs who have had a “plugins” tab in their admin panel. not there for me.
also no upload button nowhere. i’ve searched a good while.

many times i was just doubting myself. i mean, this obviously sounds like a thing people do every day and that is painfully simple.

yet i don’t find it. i haven’t a clue what i’m doing wrong.

please help.