Q: see my orders and payments  but can't download itunes music

i see my complete order history, and all the music I purchased within the "order history" in iTunes, yet cannot download them nor do i see anyway to add them to "my playlist", and they  don't show up in  "my library". I am not exactly skilled ( an understatement)  on using itunes,apple store etc., but  i purchased the stuff ( it is all music..and all from the era before the mid 1980's last purchased in 2010)  but would like to  put in the library or playlist ( or both if possible) into the itunes application's folder so I can use/play it when i'm really, really bored..

  Yes I'm old  and clueless (-no ipod, no iPhone, no android..just a laptop computer and 3 towers that need minor repairs( like moving a jumper one place then back to restore  the system,and on the other partitioning and  installing  linux to acess the hard drive again-the other is a pc running win 98..that one will not get plugged in as there  is maybe 6gb of  HD space and 2gbRAM-maybe -it was my first- and  nothing important  was ever on it)  but are non-functioning  at present..)

    So if anyone can tell me  how to retrieve the music i  paid for and have the order history on , or  what to contact to get some magic download again thing-y I'd like to  know...thanks for reading this Best regards