I sometimes have students who are gung-ho to get a grant with funding ideas. They will inquire where to go to get the most money, the most quickly. I ask them what it is they are seeking to fund exactly, and they have no idea. This approach is not likely to succeed, for several reasons.
First, grants exist for a purpose. The idea behind them is that the government wants to encourage positive social changes, such as job creation or home ownership, and wants to fund some activities that further these goals. If your project has the potential to help make this happen, then government funding may be available. Unfortunately, just wanting money is not seen as enough of a beneficial activity to compel your government to write you a check.
Next, if you develop your idea first, you are in a better position to assess what you will need to make it happen and whether your plans will adequately address the issue. If you are starting a business, then writing a business plan is an excellent way to accomplish this goal.
Third, the earlier you formulate your plan, the more opportunity you have to identify a wide range of potential funders. When you are clear on what you need, you can conduct your search efficiently and thoroughly.
Finally, when you have a well-defined idea, you can better imagine the outcome of your successful plan. It is exciting, for example, to envision yourself as a business owner, in control of your own income. Having that goal in mind makes the planning process more compelling and rewarding.
In conclusion, a little patience and a lot of forethought will help your chances to succeed in your goal of funding your project.