there are frequently differences of opinion on this matter because the code nor regs specifically define when a business begins. Here a link to a Tax Advisor article from 2015
https://www.ictaxadvisors.com/business-tax-services/when-can-you-start-deducting-your-expenses/
As is frequently the case, it depends on your facts and circumstances. There is no bright-line indicator for when you are actually in business. But, if you’re past the point of simply considering opening a business and you’re actively trying to court business or sell your product/services, then you are most likely already “in business” even if you haven’t generated a dollar or revenue. It wouldn’t be a bad idea to consult with a CPA regarding this if you’re not sure.
you state " I paid an attorney about $2000 to review and negotiate a contract with another company. This contract will be the primary source of income for my LLC." it would seem you have actively courted business
in 2021 even though revenue won't be realized until 2022. what muddies the waters is your statement "and begin operating my business in 2022" The fact you will make your business an LLC is irrelevant as to when the business started. there are many other factors that would need to be considered.
