First try restarting (turning off and back on) your phone. Sometimes that is all you need to do to access things.
Now, if after the restart you go into "Settings" and then "Update", which is usually the last thing listed, and it either won't go into it or it shows no updates for you, then there are no updates for that phone. Just because there may be newer versions of Android out does not mean your device will accept them or that the carrier/service provider and manufacturer has made them available. In the case of that, you would have to contact them.