Erm, yeah. Basically get it plugged in, see what disks you've got, get stuck in :-)
With 1Mb of memory (which many 2nd hand A500s already have) you can play a whole bunch of games, some neat demos (State of the Art is a spectacular one), play MOD music files, and mess around in Workbench.
You don't /need/ a hard disk, accellerator, or updated ROMs to get alot out of an A500.
There is plenty of software out there, but it has to be found. Try to find an established Amiga user group nearby, as having someone who knows about the old machines on-hand helps.