I can't seem to connect to my hp printer although my dell computer is connected. is there something that I need to do or maybe printer is not able to be connected because of it age?

Is the printer an AirPrint printer? Does the printer need a firmware update? Is it even a WiFi printer? What is the printer model?

Really ..... Maybe someone can help if you provide some details and we don't have to guess about what might be going on.....

First check to see if its air print enabled.

http://support.apple.com/kb/HT4356

If not, go to manufacturer website, HP may have other options. If you can provide the model number, we may be able to help more.