How do I become a non-profit organization so I can leagally do fund raising.

Well you have to be "fund raising" for a non profit goup.

So what type of group are you, what charity function are you doing.

But you file and incorporate in your state. You will do this as a non profit corporation, then you file for non profit status with the IRS under one of the varoius non profit status rules, ( example churches are under 501c code)
And you file for non profit status under your states tax codes.

You will get back a letter of determiniation which if you are a legal non profit group give you legal status.

Next to do fund raising, for example in Atlanta, you have to be bonded also and pay the city a fee to do collectons publicly in Atlanta, many major cities have similar rules.

And you will have to do annual taxes for your corporation. Not everything they do is tax exempt, so you will have to account for all the money brought in and spent, also give reciepts to all who give, and keep an account of that also.