How Will I Give A Thanking Speech To All Guests Present In The Party?

A thanking speech?  Well it would help me to know what it is you are thanking them for.  But Since I don't right now I'll do my best to give an answer anyway.  If you are thanking them for a problem they solved for you, tell them about how hard it was when you were having to fix the problem yourself.  Then go into how they helped you and then tell them how much it helped you and something like "I can't thank you enough for what you have done.  It means a lot to me."  Basically just tell how you feel about them helping you and let them know you greatly appreciate it.  If you are thanking them for something else other than solving a problem let me know and I will continue to help you out if you want it.