I would suggest first doing some research on start up costs and the start up period.  Then turn around and analyze each cost and determine how it should be treated for tax purposes.  Inventory is only one item  you may need to deal with.  Following is a link to an old article but you'll probably want to look for something more current - considering the pandemic, government assistance, etc..

Deducting startup and expansion costs (thetaxadviser.com)