I would suggest you do it in stages
first play a season of friendlies to show that your team is credible; you turn up for fixtures, you can organise pitches, teas etc, your playing standard is acceptable. Once you have built up your credibility, then apply for a place in a league.
You might want to consider doing even that in two stages, firstly as a wandering team, then as a team with some kind of home ground, even if it's only rented on a match by match basis
For a business plan, you will need to show;
that you have enough interest to create a credible team
a suitable venue for home games, plus changing and catering facilities if needed.
back up staff such as umpires and scorers if needed.
a financial plan to show income from match fees and subscriptions, along with expected costs.
You also need bags of enthusiasm, especially for a fixture secretary as you try to get started, and a captain as he or she, gets people to commit to practices and matches.
Also a decent treasurer to make sure all cash due to club is collected, bills paid promptly and proper records kept.
Good luck!