5 years isn't really all that old for paper. If it has been badly stored it might be a bit foggy or under-spec, but chances are it will be fine.
If you are a beginner, though, might be a good idea to buy a packet of fresh stuff - just to be sure you haven't got a problem with your paper. When you have your printing technique under a bit of control, you will be able to compare the 5 year old box and see how different it is.
I have paper that is over 10 years old that is fine... and paper that is 30 years old that is totally unusable... and some in between that is obviously past it's best, but, with a bit of coaxing... ;-)