1) Get training. 5k is a long way and although you can walk the sense of achievement from jogging or running is amazing and you feel like you earned every penny of your sponsor’s money.
2) Ask for sponsorship in person, people are a lot less likely to say no to your face than over the internet. Facebook posts might get you a bit but take your form into work or any social setting and the sponsorship will pile in.
3) One race day make sure you take safety pins for your number, it is amazing how many people forget
4) carry tissues, you will cry at some point. The hardest part for me was seeing all the people who were obviously still going through treatment or just finished treatment.
5) stay hydrated but don’t drink loads before you start, needing a wee halfway round is not a good thing
Lastly, enjoy the race, talk to those around you and soak up the atmosphere, you are taking part in an amazing thing and you should be proud.