To add to Tom's excellent comments, I'll be blunt and ask the questions you probably need to ask yourself; what are you actually going to offer, what are your abilities and experience in those areas and why should someone hire you?
Please don't take this wrong, my goal is not to discourage you, it is simply to make you think a bit about the realities of such an endeavour. Have you put together a business plan? Have you considered what services you actually plan to offer and the costs to do so? Have you thought about the fact that the nearest sound company being an hour away and not having enough work either tells you something about that company, which may in itself be instructive, or about the market? Have you done anything to confirm that there is any market for the services you would offer?
There are some services that you may be able to provide with minimal financial investment, but what do you bring to a potential client that they don't already have internally or that isn't already available to them? And realize that the fact that it is a temporary business does not change anything regarding taxes, licensing, contracts, liability, insurance and so forth. Do you understand the issues related these or have someone to help you there (I am so thankful for my attorney, CPA and peers for helping me though many of these)?
Please keep in mind that none of this is personal and that we don't actually know you or what actual relevant experience, education, training, certification, etc. you have. You mentioned having experience with high school theatre and portable sound in college but we do not know the scale of the systems and applications involved or of your role and you did not mention any training, education, apprenticeship, etc. I will say that it sort of jumped out at me that your plan is apparently to target churches and provide installation but you didn't mention having any church sound or installation experience.