Get in touch with your local Republican organizations, because you'll need their endorsement and help to get anywhere. I'd first contact your county party chair.
I wouldn't worry about the party. When I ran, the party stayed away - wouldn't even give me a dime and didn't want to help in any other manner, because I was running in a heavy democrat district. Still, I pushed on, and ended up with 31% of the vote. No, not a win, but I opened the district up to future cadidates in a district that was previously thought unwinnable, let alone untouchable.