Your digital footprint can affect your future because for example, if you got arrested and later get a job, people can find out what you did and might not let you work there. You should also realize that anything you have done in the past will always come back to bite you.
Three strategies people can use to keep their digital footprint appropriate and safe is to make good choices, and be aware what you do, if you were to go out with friends and they decide to do something stupid like throw eggs at a house, don’t do it because something will eventually happen. Don’t do anything highly illegal as you will get a criminal record and most likely have a tough time finding a job as you would probably get fired from your previous job which in the end will mess up your life. Be positive and nice to others and you will have a good digital footprint and make good decisions.