What should I include in a business plan for a bank loan?

The financial section is what matters
Include a cash flow projection for at least 12 months, showing when money comes in and when it goes out. Banks care about this more than revenue projections because they need to know you can make loan payments. Be conservative with income estimates; banks spot overoptimism.
Explain your competitive advantage clearly
State what makes your business different and defensible. Don't claim you have "no competition"—instead, explain why customers choose you over existing alternatives. Be specific: "faster delivery than competitors" or "lower cost through direct sourcing."
Show your management experience
Banks lend to people, not just ideas. Describe your relevant work history and why you're equipped to run this business. If you lack experience in your industry, acknowledge it and explain how you're addressing the gap.