Income received in 2024, but work is performed in 2025 and expenses are incurred in 2025 - what year does the income need to be reported?

[Cocobeansurfs]

Our small business will collect payments from customers in 2024 for retreats we are hosting in early 2025. The payments collected in 2024 will be significant ($300k+) and our expenses associated with the retreats in 2025 will be significant ($200k+), so our actual net income from the retreats will only be $100k+. How do we ensure we do not pay taxes on the $300k in 2024 before we are able to count the associated expenses in 2025? 

[Bsch4477]

Most businesses are on a cash basis where income is reported in the year it was received and expenses in the year that they were paid.