Hello,
The reason you cant find your map i assume, even if it is in bsp format is because on mac the homepath is actually /Users/name/Library/Application Support.
Drop your bsp in the "maps" folder inside the base at the previously stated location. If no maps folder exists, make one.
Also, to make a pk3 on mac, you put your bsp in a folder called "maps" your .arena and shader files in a folder called "scripts" your levelshot in a folder called "levelshots", and your textures in a folder called "textures". Remember that aside from the textures, all your files should be named the same as the bsp, just using the file extension it already has. For instance, if your map name was win.bsp, then your levelshot would be win.jpg. ANYWAYS, after you have your folders (only the maps one is actually needed), zip up all the files, and rename the archive to map-mapname.zip. then right click (control click) the zip file and click "get info" in the screen that follows, uncheck the box that says "hide extension" and replace the .zip with .pk3. A prompt will come up asking you to confirm that you want to change the extension. On mac, if you just rename the file to pk3 the standard way, itll just add .zip to the end, so you actually have to follow that.