Newby Interface question

Just bought my son a bass on ebay for Christmas (he's hanging up his drumsticks). He wants to do most of his practicing with headphones thru his MAC. I know he needs some kind of interface, but beyond that I'm lost. Aside from just needing to hear his bass thru the computer, he would also like the capability to play along with audio file (youtube, backing tracks, spodify etc.). Also any of these devices have effects capabilities (overdrive, compressor etc). Any suggestions? Makes? Models? Appreciate any help. Thanks
 
If you get an iRig, get some advice from others here about the digital one that plugs in via the Lightning connector.
I bought one of the analog ones that plug into the 1/8 in headphone/mic jack and don't really care for it.
I think it sounds crappy like it can't handle the low end very well.

The OP is talking Mac

For me on iRig, I have a totally different experience. I have the original irig on an ipod, and the new irig 2 on a ipad
Both sound and work great. iRig 2 is a lot easier to plug into an amp since it has a 1/4" output. iRig2 is less than $30, it's DVD quality audio (bit and sampling rate)

And in most cases you can return something if it doesn't work for you. Especially this time of year.

IOS on iPad can use any USB compliant interface, but a real interesting one is the iConnectAudio4plus. iConnectAUDIO4+ | Audio MIDI Interface for iOS mac PC
It will work with any group of computers and allow them to share audio. A little pricey for a beginner but a lot of interesting functionality for recording and performance.