You should get started by getting your idea register so no one steals it otherwise it will not be safe telling strangers about your idea. Investors will not be ready to invest if you are not putting your money at risk. They want to be sure that you are their equal participant in risk sharing.
Choose a name for your business and register it with your State Department. It is important that you choose a suitable and catchy name for your business and fulfil all the legal requirements. You would have to pay a certain amount of money for registration.
Make a feasible business plan and present it to the investors.
You cannot memorise all of your potential investors, so it is better that you make a list of them. After the list is complete, you should contact them one by one and cut the names who are not interested.
They just do not believe in ideas but the implementation of the idea. Work hard on your idea and do not forget to show them your progress. Remember that, not showing them the progress after equal intervals will give room to frustrations.