To start a registered and official nonprofit organization is not simple.
Making a difference towards your mission can be simple. If your idea is not capital intensive (not building houses, hospitals, etc) find a way to start working on it. Invite people to join you. Discover if how real the need is, how equipped you are to make an impact, and test the receptivity of the environment to you. If you find that you’re getting some good traction and starting to see some impact you can work towards formalizing your nonprofit (in the US nonprofit that raise less then $5,000/yr do not need to file).
If this soft-launch approach works you can go forward with registering and stepping through all the hoops you need to. The added benefit of starting early is that you have already started to build a group of people to volunteer, give, and support the nonprofit. These are people you can ask for references to accountants, lawyers and whomever you’ll need to get up and running.
Best of luck!