You "need" to seek the services of a tax professional for "at least" your first year of business. Especially if your state taxes personal income, as doing things wrong could be a double-whammy on the tax front then. If things are done wrong, then the fines, penalties and back taxes could quite easily put you out of business, before you even get it off the ground.
In my limited experience with start-ups, the average period of time for start-up costs is 3 years before the business is actually "open for business". But you're saying 10 years. While that is truly a dedication to a vocation I'm sure you love, I would fully expect the IRS to question ten years of start-up expenses to start any business.
Some of the items you mention would be classified as business assets and depreciated over time. The cost of the animals and their upkeep and care for years before starting the business, I really can't be sure about, as it's not like you're starting a farming endeavor that would handle cattle as a depreciated asset or something of that sort.
So professional help for that first year is highly advised, so you can get educated on your specific endeavor as far as the tax requirements and liability goes. Then after that first year, you can deal with the tax yourself if you feel comfortable doing so.
I have not registered an LLC yet
There really is no need to register an LLC until the year you are ready to open the business. For example, most banks will require a business registration of some sort before you can open a business account with them.
Typically, it's not necessary to register a business if you are the only owner. It's just a sole proprietorship then. But it depends on your state requirements for running a business. For example, no registration is required for a sole proprietorship in FL, but a county issued occupational license is required. Whereas registration of a sole proprietorship is required in CA.
