Try running
cd /Users/myname/Downloads/aapr-0.01-source
make
A Makefile contains rules for building files from other files but it is based on paths and contents, etc. which depend on your current location. So generally you need to be in the directory of the project for it to work.
Edit (copied from my comment):
To execute a command from a specific location (that isn't in the normal $PATH) you need to specify a path for it. So something like /bin/bash or ./aapr (where ./ means the current directory).