i need software for my amiga 500

[alx]

Welcome to A.org :-)

A null-modem cable will transfer stuff easily.  You could also use floppy disks, though it's definitely not as convienient - with something called "Cross Dos" the Amiga can read double density MS-DOS floppies.  The problem is the original spec A500 isn't up to much for modern apps unless it's expanded.  A harddrive is a must if you want anything apart from retro games, and virtually all modern applications will want OS3.x - the A500 comes with 1.3 (or maybe even 1.2?).

BTW how much do you know about Amigas?  If you know enough, can you give us the spec?

[alx]

For retro games and stuff back2theroots is good.  The files are mostly ADFs.  That's great if you have an emulator, but they will need putting onto real disks for use with a "real" Amiga.

If you're looking for more "serious" software, Aminet (that's the US mirror)  is a huge FTP archive of Public Domain apps, games, music etc.  The files are compressed with LHA - you will need a harddrive (unless you love swapping disks!) and the LHA archiver, availible there.

Remember that a lot of the things there will need OS 3.x or 2.x - if you've got a really old Amiga or are using 1.x ROM images on the emulator then it won't work.