how to save a load a game?

in my game i want it that when i collide with a "save sphere" my game automatically saves my game where it was. how would i come about doing this?

Take a look at using PlayerPrefs for small amounts of data. For something larger you may need to use either an XML file or a SQL database.

If you search Saving Players Position Unity or Saving Game Unity you will find lkots of results bot in Google and on this site.