First off I would like to take this moment to educate just a little. Summoning is an act, a ritual but not a simple spell in fact not a spell at all. Secondly Mind is very right, it is not something that should be taken lightly, and not something that a newer craft worker is advised to do. There are many things that can go wrong, possible dangers that can arise.
That being said, there is a much more simple way of getting in contact with the spirit and or entity. Invitation. A simple invitation can go a long way. However I do also suggest that you do some study before hand that you still have an idea of what your dealing with.
Also something to keep in mind, beings such as spirits and entities dont like being pestered by those who just want to have a bit of fun or those looking to just toy around with them. Be careful, be respectful.