ok so my Inspiron is about 2 years older than yours with the pentium twin core, and I regularly chop and change Linux builds for testing,
so possible problems
corrupt download of the ISO [make sure you check the SHA sum
if your using USB
bad burn to the pen-drive [I recommend you use Balena etcher to burn the ISO]
on an old machine, possible a worn USB port try a different one, although the single port near the optical drive is usually the best one to use
If your using optical drive
use a new unused DVD-r [work better on old kit]
clean the lenses on the optical drive
make sure you choose to burn as bootable disc from your software